[Gtkradiant] More changes, new build

[Nerius Landys]

I have a new Windows build that includes the most recent changes
committed in r479:

  http://porky.nerius.com/radiant-windows-builds/ZeroRadiant_Win_2011-03-03.zip

Changes (although you could look at the SVN log message too):

- imagehl plugin now part of build.  Not really sure what it does, but
it does not seem to break anything.  It was "dead code" before - code
existed but not built into a module.

- Desktop composition code is not triggered automatically anymore.
New preference controls this, "NVIDIA/Aero bug - disable Windows
composition".  Thanks to TTI from the Reaction team who helped me test
this, even though we never full ironed out a small issue which is
really not important for proper functioning.  The disable option is
enabled by default.  That is, if you're using ATI drivers that don't
have the bug, you need to manually uncheck the checkbox to re-enable
desktop composition.

- "Misc" -> "Colors" -> "Themes" color themes are now saved as soon as
they're selected.  This prevents the color theme from being clobbered
when you open Preferences after having just changed the theme.

- Since one person reported a bug with Intel video chips and since
this option fixes his problem, I've renamed the ATI drivers hack
preference to "ATI and Intel cards w/ buggy drivers (disappearing
polygons)"



Next up on my agenda for fixing stuff is an issue reported by
divVerent related to texture misalignment in certain situations.

- Rambetter