wrap Beremiz startup code into separate launcher class

this should make it easier to make customized version of Beremiz IDE.
It's easy to add own splash, change version, add/disable extensions
and many other things.

For example:

[----- MyBeremiz.py ------]
#!/usr/bin/env python
from BeremizIDELauncher import BeremizIDELauncher

class MyBeremizIDELauncher(BeremizIDELauncher):
def __init__(self):
BeremizIDELauncher.__init__(self)
self.splashPath = self.Bpath("", "splash.png")

def ShowSplashScreen(self):
# comment next line to disable splash entirely
BeremizIDELauncher.ShowSplashScreen(self)

# change version
import version
version.app_version = "3.141-rc52"

def LoadExtensions(self):
# add/modifine list of extensions
# in self.extensions
BeremizIDELauncher.LoadExtensions(self)

if __name__ == '__main__':
beremiz = MyBeremizIDELauncher()
beremiz.Start()

[-------------------------]

Beremiz installation 
====================

Windows
-------
Download installer, install. 

Linux
-----
Pre-requisites::

    # Ubuntu/Debian :
    sudo apt-get install python-wxgtk2.8 pyro mercurial
    sudo apt-get install build-essential bison flex python-numpy python-nevow

Prepare::

    mkdir ~/Beremiz
    cd ~/Beremiz

Get Source Code::

    cd ~/Beremiz
    
    hg clone http://dev.automforge.net/beremiz
    hg clone http://dev.automforge.net/plcopeneditor
    hg clone http://dev.automforge.net/matiec

Build MatIEC compiler::

    cd ~/Beremiz/matiec
    ./configure
    make

Build CanFestival (optional):: 

    # Only needed for CANopen support. Please read CanFestival 
    # manual to choose CAN interface other than 'virtual'::

    cd ~/Beremiz
    hg clone http://dev.automforge.net/CanFestival-3
    
    cd ~/Beremiz/CanFestival-3
    ./configure --can=virtual
    make

Launch Beremiz::

    cd ~/Beremiz/beremiz
    python Beremiz.py