[osg-submissions] Script to generate the Visual Studio syntax highlighting files automatically.

[Robert Osfield]

Hi Guys,

Thanks for the feedback.  I've just gone ahead and restructered the
VisualStudio directory so that the redundant parts are now discarded,
and the what I believe might still be relevant have been moved into a
new PlatformSpecifics/Windows directory.   This also gives us template
for future platforms specifics being added.

Let me know if anything that is required hasn't been mapped across and
I can go add it back in.

Cheers,
Robert.