Improve fix wrong code generation if EN/ENO are used in FBD/LD/SFC

Commit c9915bc6 "Fix wrong code generation if EN/ENO are used in
FBD/LD/SFC" caused following backtrace in some cases:

File "/home/developer/WorkData/PLC/beremiz/beremiz/PLCGenerator.py", line 476, in GenerateProgram
self.GeneratePouProgram(pou_name)
File "/home/developer/WorkData/PLC/beremiz/beremiz/PLCGenerator.py", line 258, in GeneratePouProgram
program = pou_program.GenerateProgram(pou)
File "/home/developer/WorkData/PLC/beremiz/beremiz/PLCGenerator.py", line 1713, in GenerateProgram
self.ComputeProgram(pou)
File "/home/developer/WorkData/PLC/beremiz/beremiz/PLCGenerator.py", line 997, in ComputeProgram
eno_var = self.GetUsedEno(body, connections)
File "/home/developer/WorkData/PLC/beremiz/beremiz/PLCGenerator.py", line 929, in GetUsedEno
for invar in blk.inputVariables.getvariable():
File "/home/developer/WorkData/PLC/beremiz/beremiz/xmlclass/xmlclass.py", line 1363, in getattrMethod
return DefaultElementClass.__getattribute__(self, name)
<type 'exceptions.AttributeError'>: 'inOutVariable' object has no attribute 'inputVariables'

Load images for EtherCAT extension

Fixes following backtrace:

Traceback (most recent call last):
File "/usr/lib/python2.7/dist-packages/wx-3.0-gtk3/wx/_core.py", line 16765, in <lambda>
lambda event: event.callable(*event.args, **event.kw) )
File "/home/developer/WorkData/PLC/beremiz/beremiz/BeremizIDE.py", line 1074, in AddConfNode
self._Refresh(TITLE, FILEMENU, PROJECTTREE)
File "/home/developer/WorkData/PLC/beremiz/beremiz/IDEFrame.py", line 917, in _Refresh
self.RefreshFunctions[element]()
File "/home/developer/WorkData/PLC/beremiz/beremiz/IDEFrame.py", line 1526, in RefreshProjectTree
self.GenerateProjectTreeBranch(root, infos)
File "/home/developer/WorkData/PLC/beremiz/beremiz/IDEFrame.py", line 1565, in GenerateProjectTreeBranch
self.GenerateProjectTreeBranch(item, values)
File "/home/developer/WorkData/PLC/beremiz/beremiz/IDEFrame.py", line 1554, in GenerateProjectTreeBranch
self.TreeImageDict[icon_name] = self.TreeImageList.Add(GetBitmap(icon_name))
File "/usr/lib/python2.7/dist-packages/wx-3.0-gtk3/wx/_gdi.py", line 6735, in Add
return _gdi_.ImageList_Add(*args, **kwargs)
ValueError: invalid null reference in method 'ImageList_Add', expected argument 2 of type 'wxBitmap const &

Flush standard output when runtime ready, so that IDE knows it, and can continue connection to LOCAL:// uri

Change behaviour of python_eval function block : if TRIG is false, then ACK is also false except a pulse precisely when receiving answer from interpreter

Removed useless condition in Worker.py that was allowing misfit non-serialized call when worker still not running its loop.

Refactoring. Separated PLC Object, PYRO Server and MainWorker :
- PLC Object is now a Singleton, instantiated through runtime.CreatePLCObjectSingleton(...)
- Pyro server doesn't hold any reference to PLCObject, and doesn't create it anymore
- PLC Object class doesn't inherit from Pyro.ObjBase anymore
- Pyro related code moved to runtime.PyroServer.py
- MainWorker class moved to runtime/Worker.py
- Both PLC Object and MainWorker creation happens in runtime/__init__.py

Fixed new code-generation code, that was making exception with simple variable-to-variable assignments.

BACnet : Fixed missing header include in server.c introduced in 37ef7a3c6b8b

merged

NevowServer : Added minimalist css style customization and a link to go to settings page and back

fixed setServer call in WampClient module. Was doing nothing because _PySrv wasn't global.

Removed now deprecated ForceReload from WAMP exposed calls

fixed documentation bug

NevowServer : added addInfoString to allow extensions to declare some read-only strings to be displayed in settings. Also renamed addExtension in addSettings for clarity.

fixed problems reported by certification testing : vendor identifier acces rights (now read only), and bvlc_maintenance timer was increasing too fast.

Some blank lines to make bitbucket's PEP8 2.2.0 happy

merged Andrey's default

Fix wrong code generation if EN/ENO are used in FBD/LD/SFC

This problem appears for example here

--------
------- | MOVE |
| MOVE1 |------|EN ENO|
------- | |
| |
------- | | -----------
| 23 |------|IN OUT|---| LocalVar0 |
------- -------- -----------


--------
------- | MOVE |
| MOVE2 |------|EN ENO|
------- | |
| |
------- | | -----------
| 15 |------|IN OUT|---| LocalVar0 |
------- -------- -----------

Before wrong code was generated for this case:

MOVE6_OUT := MOVE(EN := move1, IN := 23, ENO => MOVE6_ENO);
LocalVar0 := MOVE6_OUT;
MOVE4_OUT := MOVE(EN := move2, IN := 15, ENO => MOVE4_ENO);
LocalVar0 := MOVE4_OUT;

With this patch now following code is generated:

MOVE6_OUT := MOVE(EN := move1, IN := 23, ENO => MOVE6_ENO);
IF MOVE6_ENO THEN
LocalVar0 := MOVE6_OUT;
END_IF;
MOVE4_OUT := MOVE(EN := move2, IN := 15, ENO => MOVE4_ENO);
IF MOVE4_ENO THEN
LocalVar0 := MOVE4_OUT;
END_IF;


See discussion here:
https://sourceforge.net/p/beremiz/mailman/message/36378805/

Fix flickering in debug panel

This flickering made debug panel unusable, because most of the time
panel was white. This problem effects wxPython with GTK3+ backend
(at least on GNU/Linux systems).

Removed code IIUC draws box with content of moved debug variable, I
don't see any effect of it neither on GNU/Linux nor on Windows. It
should be safe to remove.

Fix non-usable toolbar on wxPython with GTK3+

On GNU/Linux if wxPython uses wxWidget with GTK3+ backend (this is
what most modern distributions do), then size of EditorToolBar was
always to store only one button.
This is because GetBestSize() is updated only after pane is shown and
updated.
The code does work correctly on python-wxgtk3.0 (gtk2 backend) on
GNU/Linux and with wxpython 2.8 on Windows.

Fix problem with decreasing size of StatusToolBar when tools are removed from toolbar.

StatusToolBar - toolbar with tool to build, clear, connect, ...
This problem appears only in python-wxgtk3.0. In python-wxgtk2.8 there
was not such problem.

If call StatusToolBar.SetMinSize(wx.DefaultSize), all is working, but
following warning message appears:

(Beremiz.py:15155): Gtk-WARNING **: 18:42:24.115: Negative content
width -6 (allocation 1, extents 4x3) while allocating gadget (node
toolbar, owner GtkToolbar)

To avoid that StatusToolBar.GetToolBitmapSize() is used instead of wx.DefaultSize

Add BACnet example

Rework README.md, add examples section, add instructions for Modbus extension, more information about runtime.

Add Modbus example

Disable source quality checking on ethercat plugin - will fix it later

Passed bacnet*.py through autopep8, and attemped to fix manually what went wrong + fixed pylint complains

More pylint+pep8 conformance

autopep8 + hand made fixes on ProjectController.py runtime/WampClient.py wxglade_hmi/wxglade_hmi.py

pylint on runtime/NevowServer.py

pep8 on runtime/NevowServer.py