Allow any resolution for mainhalls (From Yarn)

Also includes support for more than two mainhall resolutions, zooming
so one mainhall can adapt to multiple resolutions, setting new mainhall
fonts, help overlays for all resolutions and adjustable tooltip padding.
Also allows preload screens to be any resolution & aspect ratio.

git-svn-id: svn://svn.icculus.org/fs2open/trunk@10844 387891d4-d844-0410-90c0-e4c51a9137d3
From MageKing17: Patch form Mantis 3067 (Nebula flashing not following player view point)

git-svn-id: svn://svn.icculus.org/fs2open/trunk@10845 387891d4-d844-0410-90c0-e4c51a9137d3
From MageKing17: Patch for Mantis 761(!): Text color tags do not work in debriefings. Also allows color spans in text to cover line breaks.

git-svn-id: svn://svn.icculus.org/fs2open/trunk@10846 387891d4-d844-0410-90c0-e4c51a9137d3