idTech2 surface inspector regressions

[jdolan]

I haven't been very active in GtkRadiant development lately, but I built HEAD this weekend to do some map tuning on Quetoo and noticed some pretty major regressions with the Quake / Quake2 / Quetoo surface inspector:

• It no longer correctly populates the texture name drop-down, ever.
• It requires the full Quake path for texture names, e.g. "textures/group/texture" instead of "group/texture" -- I'm not sure, but I don't think this was the case previously.

Another thing that appeared awkward to me was the window state itself. It might be nice if these floating windows were set to always-on-top, and if the hot keys to make them appear also hid them when they were visible? Did we ever have that behavior? I found myself constantly losing the surface inspector behind the editor.

[jdolan]

The texture dropdown issue is fixed in the pending PR.