Initial commit of NaCl VM. Currently only implemented for the server.
Merge branch 'engine-upgrade' of github.com:Unvanquished/Unvanquished into nacl

Conflicts:
	src/engine/qcommon/vm_traps.h
Merge branch 'engine-upgrade' into nacl

Conflicts:
	src/engine/qcommon/vm.c
	src/engine/qcommon/vm_x86.c
NaCl: Remove all unique_ptr, use move-only handle classes instead
NaCl: Various bug fixes
NaCl: Implemented game API
NaCl: Use an environment variable instead of an argument to pass the root socket handle
NaCl: On Linux, kill the child process when its parent dies
NaCl: Minor fix to include order
NaCl: Add support for nacl_helper_bootstrap
NaCl: On 32-bit windows reserve 1G of address space in the child process
NaCl: Use a job object on Windows to make sure the child process dies if the parent is killed
NaCl: Don't preallocate memory when not running sel_ldr
Remove all asm code from the engine, C versions are just as efficient.
Rewrite of build system and major cleanups
Remove DaemonMap
Remove GLSL optimizer
Remove USE_OPENAL_DLOPEN, it is now the default
Remove USE_CIN_XVID and make USE_CIN_THEORA and USE_CODEC_VORBIS the default
Fix TTY client build