Remove ability to generate sublime clang files.

SublimeClang is a optional plugin to SublimeText and I felt it
shouldn't be part of the generator for the following reasons:

1. Reduces the amount of sublime and sublimeClang specific
   code we have to maintain inside CMake.
2. In testing the SublimeClang commands generated did not work
   for the VTK project.

For people that do want this feature I recommend that they
looking into https://gist.github.com/robertmaynard/4724705 for a
way to use CMAKE_EXPORT_COMPILE_COMMANDS to generate JSON files
that can be used by SublimeClang.

Source/cmExtraSublimeTextGenerator.h

@@ -48,9 +48,7 @@ private:
 
   void CreateNewProjectFile(const std::vector<cmLocalGenerator*>& lgs,
                                 const std::string& filename);
-  void WriteSublimeClangOptionsScript(const std::string& filename);
-  void WriteSublimeClangOptionsFile(const MapSourceFileFlags& sourceFileFlags,
-                                    const std::string& filename);
+
   /** Appends all targets as build systems to the project file and get all
    * include directories and compiler definitions used.
    */