fixed FileAssociatedShader "incompatibility" with vim

Vim does not always simply write to the saved file but replaces them with its swap file.
The removal of the shader source file would cause QFileSystemWatcher to unwatch it.
Hence, editing shader source files with vim would break the intended behavior.
Merge Pull Request 2 from j4yk
Fix inline misuse
Merge branch 'master' of github.com:hpicgs/cg2sandbox
Reduce gcc compiler warnings
Refactor pull request 2 (closes #2)