Workaround segfault in SDL when switching to opengl.

Clearing the screen after setting videomode with opengl segfaulted. I didn't
check in detail, but looks like a problem in SDL and re-initializing the video
subsystem did the trick.
Bad scrollbar, only scroll when the mousewheel is actually over you.
UI fixes
UI Fixes III: Fix Harder
Added message when no audio hardware is available.
Language fixes
fix bad comparison
fix fix
fix mod loading/multithreading issue
fix makefile
remove/rename startup hacks

multithreading takes care of the disappearing loading text.
stupidityFlag was a silly name, i should get less angry when coding.
intro hacks to keep it letterboxed stay.
fix disabling weapon slot mods
fix scrollTo/drag on scrollbars
Merge pull request #830 from cpages/glfix

Workaround segfault in SDL when switching to opengl.
Added audio format options.
Fixed audio subsystem not being properly reinitialized.
Fixed old resources staying in memory after reload.
Make landed UFOs take off after a failed mission.
Fix autosave/ironman ignoring game over.
Globe scroll speed proportional to zoom level.
Fixed bugs in audio preference.
Fix window caption disappereance in Linux
After commit 05bb5efca7 on Linux caption of main window reinitializing
to empty caption after switching from/to OpenGL.
This commit fixes that.