cpuaffinity/sdl_mixer changes

Hopefully this will alleviate SDL2 sound issues.

If not, hopefully this will give us info on what the hell is going on.

See merge request !51

Monster misc 2

Just some clean-up in doomdef.h, nothing important or majorly game-breaking really. It's all stuff that apparently hasn't been used by the game itself in many years by now.

...

inb4 I find something else obsolete to kill later and make monster misc branch no. 3

See merge request !52

Move InitSubSystem calls into proper places,
don't use AUDIO_S16LSB (bad according to SDL_mixer docs)
Add error checking

still exists in DD (while it exists) but no longer saves.
No reason whatsoever for affinity to be settable by the game itself.

Colour Changing MD2s

What it says it is, I haven't touched it in quite a while, but I have checked and it seems to be working.

See merge request !30

Travis-CI builds

Merge support to build SRB2 for Linux system via Travis-Ci
This will build SRB2 with GCC and Clang to make sure we do not break Linux/GNU builds

See merge request !41

Update pkg to be fully compatible with Debian Jesse, add desktop file/artwork