Install the shaderLanguages plugin via Package Control and you benefit from syntax highlighting in glsl files. If you want it to apply to .sha files to, just add sha to the fileTypes array in “OpenGL SL.tmLanguage”. That file is found inside the ShaderLanguages plugin directory.
C:\Users\<USERNAME>\AppData\Roaming\Sublime Text 2\Packages\ShaderLanguages\OpenGL SL.tmLanguage