Added a new function SetFilePermissions to set permissions of a file. I'm not sure about the Windows implementation. See this feature request: https://bugs.alliedmods.net/show_bug.cgi?id=6152
Initialized the mask variable.
Moved the FPERM_ defines into the .cpp and removed the header file.
Merge pull request #43 from hlstriker/master

Added a new function SetFilePermissions to set permissions of a file (r=psychonic).