Merge remote-tracking branch 'origin' into openal

Conflicts:
	src/sound/fmodsound.cpp
Fix compilation with OpenAL
Remove GStreamer support
Small fixups

find -> std::find
AL_EXT_loop_points -> AL_SOFT_loop_points
Remove an unnecessary function
Use SDL_sound when available to decode files
Support float stream callbacks with AL_EXT_FLOAT32
Make sure streams are "pumped"
Handle S8 and U16 samples from SDL_sound
Implement GetStats for OpenAL streams
Results for console tab-completion are now color-coded. CCMDs appear blue, CVars green and aliases red.
- used TEXTCOLOR_ #defines for colorizing CCMD list, remove use of strbin1.
- Fixed: crash when closing ZDoom in the save menu and a memory leak.
- changed autoloading of *.deh lumps: it is now controlled by a CVAR with 3 options: never load *.deh lumps, load all of them or only load the last one. *.deh loading is disabled by default.
- Use a more conformant C++ preprocessor macro identifier for Unix systems.

The 'unix' identifier isn't defined when '-std' is passed to the compiler (tested with gcc and clang), so use '__unix__' which is well enough documented.
Merge branch 'maint'
Merge branch 'maint'
Merge branch 'maint'
- Be clear about the safe 'memset/memcpy' operations on virtual classes.

Since I remember that 'memset/memcpy' is safe in this code, it should be okay to cast to the generic pointer all the 'virtual class' arguments before calling the above functions. Shuts up Clang warnings.
- Be more compatible with C++11 narrowing conversions system.