[GRASSGUI] XML parser bugs on special characters

[Yann]

Hello,

When launching the r.evapo.PM command from the HydroFOSS/ add-on, if it is in 
tcltk, it accepts displaying the dialog. In wxGRASS it bugs like this:
--------------------------------------
Traceback (most recent call last):
  File "/usr/local/grass-6.3.cvs/etc/wx/wxgui.py", line 348, in OnMenuCmd
    menuform.GUI().ParseCommand(cmd,gmpath, parentframe=self)
  File "/home/yann/coding/grassaddons/gui/gui_modules/menuform.py", line 1108, 
in ParseCommand
    xml.sax.parseString( getInterfaceDescription( cmd ) , handler )
  File "/usr/lib/python2.4/site-packages/PIL/__init__.py", line 49, in 
parseString

  File "xml/sax/expatreader.py", line 107, in parse
  File "xml/sax/xmlreader.py", line 123, in parse
  File "xml/sax/expatreader.py", line 211, in feed
  File "xml/sax/handler.py", line 38, in fatalError
xml.sax._exceptions.SAXParseException: <unknown>:15:35: not well-formed 
(invalid token)
------------------------------------

When I used to have r.evapo.PM in GIPE/ I found out a dirty way to make it 
work by removing the unit special characters in the description keys (i.e. 
the small uppercast o that makes a degree Celsius unit). But it maybe not a 
long-term solution. I am not sure. Please advise.

Yann

-- 
Yann Chemin
Sainte-Anne d'Auray, France