Consider using ALLUSERSPROFILE environment variable for base path on Windows

[GoogleCodeExporter]

Applies to Windows only:

Currently OSValidator.getProgramBasePath() as well as the sdfs.Main class use 
the PROGRAMFILES environment variable to base the calculation of the base path 
on.

It may be more appropriate to instead use the ALLUSERSPROFILE environment 
variable, which points to a dedicated directory for storing global data that is 
shared among all user accounts.

This will also avoid problem with lack of write access to the \Program Files 
folder under Windows Vista and later versions.

Original issue reported on code.google.com by [email protected] on 5 Jan 2012 at 2:05