OPCUS client: fix handling of string type Node Identifier

Add OPC-UA simple synchronous client extension.

This extension uses python-opcua to growse server nodes, and generates runtime C code that use open62541.
- python-opcua must be available in python path (i.e. "import opcua" must succeed). Can be installed from pypi with "python2 -m pip install opcua --user" .
- at build time, open62541 is expected to be build in "open62541" directory, aside "beremiz" directory.

IDE: fix wxpython4 sequel : project "add" menu was having no extension entry visible.

Prevent exception when asking for CSV dump while variable traces are still empty

Fix wrong comment

Fixed two exceptions happening when interacting with viewer(s) in debug mode, when debug data is still not initialized.

SVGHMI: update test/svghmi to reflect latest changes

SVGHMI: Update generated xslt

SVGHMI: remove "value" element in meter and circularbar widget. Adding support for printf like formating make widget label too heavy. It is better to use Display widget instead.

SVGHMI: Move sprintf.js out of widget_display.ysl2 since it is used in other widgets as well

Dropped SVGUI, deprecated and replaced by SVGHMI. Transformed traffic_lights exemple so that it uses SVGHMI instead.

Merge from default

SVGHMI: Update generated XSLT (PathSlider widget)

SVGHMI: simplication in ScrollBar widget JS code

SVGHMI: Added PathSlider widget

SVGHMI: update generated xslt (List related changes)

SVGHMI: add files missing in ee9e98c856a : Add TextList widget, add support for TextList in DropDown widget, move List, TextStyleList and TextList widget code in dedicated file with documentation.

SVGHMI: add test for Dropdown using TextList

SVGHMI: Add TextList widget, add support for TextList in DropDown widget, move List, TextStyleList and TextList widget code in dedicated file with documentation.

Sequel to 95fe62bfe920 : Copy description when DnD variables from Globals in resources and configuration variable panels to POUs, now including ST/IL POUs.

IDE: Add a "Tutorials and Examples" sub menu to "File" menu to directly open projects in /exemples directory. Move 'python' and 'first_steps' projecvts from /tests to /exemple

WxPython 3.x -> 4.x : removed exception on stdout when closing at IDE frame

Merged default

Xenomai runtime: more verbose error message when problem with RT-Pipes.

Re-introduce sertup.py from Ivan Tyagov, accidentally deleted during SVGHMI branch merge

Tests/svghmi_scrollbar: Fix variables names and remove useless "OnStart OnStop OnWatchdog" to use defaults.

IDE/windows: Avoid exception on quit caused by runtime being killed without disconnecting.

Runtime/unix: Fix typo preventing start of Pyro server

Fix SVGHMI exception when running on Windows, missing ENODATA in errno.

Workaround missing "IsMaximized" attribute for AuiPaneInfo in wxPython 4.1.0

Runtime: avoids using "pipe to self" bailout unblocking trick on windows, since select() only takes sockets.

More WxPython 3.x->4.x API update

Workaround RubberBand drawing problem on GTK3

Depricated PyGridCellEditor becomes GridCellEditor

Fix exception when canvas becomes null because of window resize, and avoid useless parameter+condition in GetLogicalDC

Preliminary support for WxPython 4.1.0. Needs more testing. Grid selection/focus seems broken, and probably many other bugs hidden in dialogs and editors.

Merge SVGHMI in default

Close SVGHMI branch

Copy description when DnD variables from Globals in resources and configuration variable panels to POUs. Also prevent making exception in case some other DropSource wouldn't provide description.

SVGHMI: Allow toggling fulscreen mode my right click or long press.

Xenomai runtime: fixed bugs introduced in e3db472b0dfb (RT->nRT wakeup) + other small typos

IDE: systematically log command when launching process (was not showing in case of LOCAL:// runtime being launched)

Win32 runtime: fix build with gcc 9.3.0 from msys2

Runtime+SVGHMI: Add generic wakeup of threads from PLC thread to windows implementation of plc_main.c. Also added nRT_reschedule to abstract sched_yield.

Runtime+SVGHMI: Added a generic way to wakeup non-real-time threads from real-time PLC thread. Replace SVGHMI specific calls in Linux and Xenomai implementations of plc_main.c. Fixed xenomai build, xeno-config making problems with --no-auto-init argument.

Runtime: Better handling of nested strings in spawn_subprocess commandline parsing

IDE: Fixed use of RingBuffers in variable traces graphs when switching to 2D trend graph.

IDE: On windows, align better "reset to default" button in CTN config panel.

SVGHMI: Fix detection of library without instance and instances without library. Added one more widget in the widget library. Renamed "view_name" in "name" in commands substitutions.

SVGHMI: Fix missing "OnWatchdog" in XSD, accidentally deleted in earlier commit.

IDE: Add a "undo" button for each field in CTN config panel to reset to default value.

SVGHMI: detect watchdog abuse (more than one HMI instance with watchdog) at build time

SVGHMI: code refactoring allowing more in depth customization for substitution on start/stop/restart commands, and default SVG choice.

Runtime: more robust loading of Wamp config, specially in case config file was corrupted.

SVGHMI: add arguments to pass to ressource factory when attaching rerssource to svghmi root

SVGHMI: fix typo in slider widget

Runtime: Handle errors in user's python code more gracefully : make exceptions and allow repair.

SVGHMI: Fixed halting problem when there is no session opened.

SVGHMI: Widget lib: small doc fix.

SVGHMI: DnD UI: Use widget's short description, initially forgoten.