Fixed various missing files
Adding a CONTRIBUTING file so the rights that GitHub users grant to Valve with Contributions are clearly outlined.
Add executable permission to ccache and protoc.
Mac: Fix corrupted protoc binaries.

These binaries were corrupted due to accidental newline ending conversion.
Add executable bit to gendbg.sh.
Fix typo and value which should be non float
Rename GameInfo.txt to gameinfo.txt
Merge pull request #49 from ntgd/master

Fix 'gameinfo.txt' doesn't exist in subdirectory 'source-sdk-2013/mp/game/mod_hl2mp/'
Check in gitattributes for binaries.

Followup to @TheSeg's comments on 5f08baa.
* Switched the SDK from checked-in projects to VPC, the Valve Project Creator. See the Getting Started document on the wiki for details.
* Pulled in bug fixes from HL2 and HL2MP.
Fixed execute permissions on OSX/Linux scripts and binaries.
Merge https://github.com/ValveSoftware/source-sdk-2013
Updated the libs. Updated vpc_* to include support for $Conditional in .vgc files. Included vstdlib_exclude.vpc for the OSX builds.
Update text & binary attributes.

This should prevent line ending issues.
Normalize line endings

Fixes issue #75.
Added some more files to .gitignore. Added technical guidelines for pull requests to CONTRIBUTING
Merge https://github.com/ValveSoftware/source-sdk-2013
Merge pull request #36 from AnAkIn1/fogplayerparams_fix

Fix typo and value which should be non float