add a useful utility class

git-svn-id: svn://svn.icculus.org/fs2open@10302 387891d4-d844-0410-90c0-e4c51a9137d3
add some useful methods &c.

git-svn-id: svn://svn.icculus.org/fs2open@10303 387891d4-d844-0410-90c0-e4c51a9137d3
this should complete work on the installation page!

git-svn-id: svn://svn.icculus.org/fs2open@10304 387891d4-d844-0410-90c0-e4c51a9137d3
making things more robust

git-svn-id: svn://svn.icculus.org/fs2open@10305 387891d4-d844-0410-90c0-e4c51a9137d3
don't need this anymore

git-svn-id: svn://svn.icculus.org/fs2open@10306 387891d4-d844-0410-90c0-e4c51a9137d3
minor updates

git-svn-id: svn://svn.icculus.org/fs2open@10307 387891d4-d844-0410-90c0-e4c51a9137d3