Remove duplicate include files; patch dependencies.
Regularize VegaFEM options and project name.

This also adds a configuration option named
`VegaFEM_ENABLE_OpenGL_SUPPORT` to match Ricardo's build.
OpenMP support per Ricardo; fix bad option names.
Move GLUI to thirdparty (from src/other).
Need rule to install headers...

... now that they are not duplicated in the `include` directory.