[Cmake] Improvements of FindwxWindows.cmake

[Mathieu Malaterre]

Hi all,
	I have been hacking FindwxWindows.cmake to fit my needs. My hacked 
version could be find:

http://www.creatis.insa-lyon.fr/~malaterre/cmake/FindwxWindows.cmake

Changes:
- Now take into account wx debug library
- Add needed preprocessors definition (according to
http://www.wxwindows.org/technote/vc_ide.htm)

	BTW I didn't really understand why WXDialog uses:
CMake/Source/WXDialog/wxincludes.h

what was the issue compared to an:
ADD_DEFINITION(-D__WXMSW__  -DWINVER=0x0400 ...)


	Now what I want is that the library (between debug and release) is 
choosen at compile time (instead of an option in CMakeSetup), is it 
possible ? Could you give me some info about how to do that, thanks.


Thanks,
mathieu