Replace the hard-coded quake2 / heretic2 surface inspectors with a generic idtech2 version

I've streamlined the UFO:AI surface inspector to look and behave more like the NetRadiant version. This inspector is configurable, and will work with any idTech2 game, provided the .project template file specifies the surface and contents flags for the engine. For that reason, I felt it made sense to remove the redundant, hard-coded quake2 and heretic2 inspectors. I've updated the Q2Pack in Subversion to be compatible with these changes. Works well.

![screen shot 2013-07-08 at 10 03 51 am](https://f.cloud.github.com/assets/643118/766074/3786d560-e84e-11e2-8169-baad14ce219d.png)


I've also fixed all of the GtkWarning messages that were being spewed to the console. I think the Q3 inspector suffers from these too. I can take that on next.