Added detection for the Glyph scripting language.

This adds detection for the Glyph scripting language supported by Gridgen and Pointwise software (http://www.pointwise.com/). This software is used to generate meshes for computational fluid dynamics. 

Often a time consuming process, Gridgen and Pointwise users have the ability to reduce their grid generation time by using Glyph scripting. A Glyph script can be used to run the software in batch mode, encapsulate repetitive tasks, extend the software's functionality, even develop specialized meshing applications.

Because Glyph is based on Tcl with Pointwise specific commands added to it, the syntax highlighting is the same and the change to the source is minimal. I've simply added the ability to detect the .glf file extension.