update hl2sdk-csgo
update submodules
start fixing mac build errors

- protobuf shit is still fucked
generate usermessages myself from latest valve source
fix build errors

- compile files with .cc extensions (lol mm devs)
- regenerate usermessage stuff - the metamod usermessage stuff is a bit
  outdated compared to what valve has on their dev wiki
update travis builds

- travis upgraded to 64-bit vms so we have to install the 32-bit libc
  development packages now
Fix compiling under gcc 4.7

- Need to specify an extra flag to use protobuf headers with -fno-rtti
Merge pull request #62 from pmrowla/master

protobuf build stuff