[Gtkradiant] Reliance on textures/ in texture names

[Hydra]

At the moment, alot of the code adds and removes textures/ from texture
names and paths.

Thinking about it, this isn't really necessary as the only reason I can see
it being in there is because q3 shader scripts are defined as
textures/<blah>

Map files never store textures/mytex/foo, only mytex/foo.

Maybe the shaders plugin should handle this ?

Should this be entered as a bug ?