Also applied our style guide on that class.
Renamed some public globals to match our style guide.
Made BitmapManager inherit from BLocker instead of duplicating its
functionality (incorrectly, did not check for B_INTERRUPTED) locally.
Some more cleanup.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@13259 a95241bf-73f2-0310-859d-f6bbb57e9c96