Started adding pretty-printers for the various types in the music model.
Merge branch 'music_dev' of https://github.com/GL-MPRI-2014/GL_MPRI_2014 into music_dev
Started adding pretty-printing facilities for all defined structures.

For debugging purposes.
Completed print_pitchClass implementation
Quick visual refactoring on function print_pitchClass.
Continued work on pretty_printing
Fixed tagProd
Added time-constants and time creation functionsO
Finished implementing pretty-printing functions
Merge branch 'music_dev' of https://github.com/GL-MPRI-2014/GL_MPRI_2014 into music_dev