Added error code to the HexMesher and the function write_obb_mesh.
Added function notes to the hexmaker.
Added more documentation to the hexmaker op. Altered the class so that the write_files function takes a base_filename rather than the class itself. Makes it easier change the base_filename if the user wants to.
Changed the name of the HexMaker function write_files to write_to_files (a little more descriptive).
Added two new files to separate the hexmaker class from the create_hv_mesh file.
Removed deprecated include.
Made the new Hexmaker class compile-able and added it as a dependency to the create_hv_mesh program.
Added object files to the make clean command.
Removed un-needed moab namespace qualifiers in hexmaker.