setup.py fails on hardcode Windows-style backslash in filepath

[RondaHilton]

assigning variable "versFile" with a backslash '\' makes this entire package fail to install on any Unix-flavor system. The platform could be tested, and backslash or forward-slash made conditional, something like (the Python spacing has been removed automatically here):

import platform
osstr = platform.platform()
if osstr.find('SunOS') >= 0:
osseparator = '/'
else:
osseparator = '\'
...
versFile = 'GISPython' + osseparator + 'SysGISToolsSysParams.py'