Add texture rotating ability in editor

[BratishkaRUS]

I love to use your editor to fix HL maps, but it has a problem that I can't rotate textures, and honestly is a very big loss

Hoping that you would add this ability in future updates

[UnrealKaraulov]

I think it can be easily added, render works, possible just missing edit boxes for this parameters

[UnrealKaraulov]

@BratishkaRUS
@wootguy

I added texture rotation in my bspguy fork

UnrealKaraulov@a4a1f8b

(At this moment, without lightmaps generate)

(And also small manual verts editor, possible to edit visual date of any part of map, but without collision :( )

[UnrealKaraulov]

@wootguy if you want, we can merge fork in bspguy.

[UnrealKaraulov]

Face verts edit example:
Before:

After:

But only visual data, because I don't know at this moment how to generate collision for edited verts.

[wootguy]

If you can isolate just the texture rotation code for a pull request, then yeah I'll review it. It's ok that lightmap generation doesn't work. Scaling breaks lightmaps too.

[UnrealKaraulov]

@wootguy
In my fork I added:
Texture Rotation
Face Editor Update(better texture support(change name, search in wada, etc), verts manual editor, etc, but without texture browser)
Export obj, wad, ent, bsp(selected model with working collision, can be used in any entity instead of MDL models)
Import wad, ent, bsp(now only one mode - import as new entity outside map)
Render bsp models(no MDL render at this time)
Full support for "angle" and "angles" keyvalue.
Render ents and models using these keyvalues.
Full featured LightMap Editor.
Sorting by fgd flags.
Added "undo/redo" for any manipulation. (Move ents/origin, etc)
Added move model(as option for transforming)
Added CRC-Spoofing(now possible to replace original map and play it on any servers)
Updated controls logic(now can't using hotkeys and manipulation, if any input/window is active)
Replaced and edited many functions(using static analysis proposals, compiler warnings)
...

@wootguy I can't support two version at one time :(

[wootguy]

ok, no problem.

[UnrealKaraulov]

@wootguy you can cut the necessary changes from my fork, but as you can see, I'm very bad do commit names and it content, and they are in a very poor state... :(