Added MacSystemProfiler, minor changes

- Added MacSystemProfiler class to Additional Modules.
- Added Carbon.VersionAsInteger to standardize version-to-integer
conversions. (Moved code from SystemVersionAsInt.)
- Mofied Carbon.SystemVersionAsInt to use Carbon.VersionAsInteger. No
change in functionality.
- Added Carbon.IsMountainLion.
- Modified MacPListBrowser.