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()

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

<?xml version="1.0"?>
<purchaseOrder orderDate="1999-10-20">
  <shipTo country="US">
    <name>Alice Smith</name>
    <street>123 Maple Street</street>
    <city>Mill Valley</city>
    <state>CA</state>
    <zip>90952</zip>
  </shipTo>
  <billTo country="US">
    <name>Robert Smith</name>
    <street>8 Oak Avenue</street>
    <city>Old Town</city>
    <state>PA</state>
    <zip>95819</zip>
  </billTo>
  <comment>Hurry, my lawn is going wild!</comment>
  <items>
    <item partNum="872-AA">
      <productName>Lawnmower</productName>
      <quantity>1</quantity>
      <USPrice>148.95</USPrice>
      <comment>Confirm this is electric</comment>
    </item>
    <item partNum="926-AA">
      <productName>Baby Monitor</productName>
      <quantity>1</quantity>
      <USPrice>39.98</USPrice>
      <shipDate>1999-05-21</shipDate>
    </item>
  </items>
</purchaseOrder>