gladevcp - hal_sourceview - add new function set_language

widget.set_language(lang, path):

lang = the lang file to set

path = the search path for the langauage file,
       to be able to supply GUI specific ones
       if None, it is set to default
gmoccapy_0_9_9_7_2 - new source highlight lang file

ver 0.9.9.7.2
- introduced an better gcode highlight for sourceview