Add better version handling to win32ui

The delimiter of just '-' (no spaces) was not as strict as it could
be making adding things like releases to the version file, 2.7.1-1
for example not possible. This makes the delimiter " - " (with spaces)
which allows for that type of flexibility.
Merge pull request #97 from awiddersheim/fix_win32ui_version

Add better version handling to win32ui