Primordial tweaks for Windows

Force inclusion of dependencies headers
libjpeg, libvorbis and zlib won't be supported on Windows for the moment
(until I find the binaries and for having a friendly build enviroment)
winsock and winmm inclusion

Added link flags on Windows
EFX was lacking on Windows

This did the trick, so now ht compiles with OpenAL
Edit .gitignore