fixed build on OS X
added workaround for menu crashes
Revert "Use SDL_sound instead of libvorbisfile"

This reverts commit 17267f6a7c7a72e9b5f25aa7cdfef7a6f0c0029c.
added Vorbis CMake module until SDL_sound usage is stabilised
allow playback of videos
fix deprecation warnings
check for __linux__ define not LINUX
removed deprecated macro AVCODEC_MAX_AUDIO_FRAME_SIZE
remove useless Logger to IStorm3D_Logger wrapper
remove signal handler code, it is useless
Make igios_backtrace demangle C++ function names
end backtrace before __libc_start_main

having a backtrace up to main is enough
Log missing files to a temporary log file for debugging

This commit is temporary and will be reverted soon
Do not log error message when opening some optional files
Remove coneAtiVertexShader

It is never used and the shader ource file for it does not exist.
Create a script to fix missing file warnings
No more missing file warning for Config/main.txt and empty save slots
fix missing scavenger_gore_partial.txt
fixed compilation with Clang
Add variadic log functions to Logger

This will allow removing strPrintf sometime