Remove XFT, SHM, and MMX
Remove useless defines

- HEXCHAT
- USE_DB
- SCROLL_HACK
- MOTION_MONITOR
- ITALIC
- COLOR_HILIGHT
Replace xtext's transparency with full window transparency

Xtext's transparency barely worked on windows, didn't work on any modern
linux wm and used fake transparency.
This uses gtk's built in window opacity that works on more systems and
is real transparency.
Text area only transparency may return with a transition to cairo, if it
works on Windows.
Remove overdraw
Merge branch 'xtext2'