Added support for mixed case opcodes.
Added support for mixed case opcodes.

ketchupok/csound,csound/csound,ketchupok/csound,csound/csound,csound/csound,ketchupok/csound,ketchupok/csound,ketchupok/csound,ketchupok/csound,csound/csound,csound/csound,csound/csound,csound/csound,ketchupok/csound,csound/csound,csound/csound,ketchupok/csound,ketchupok/csound,csound/csound,ketchupok/csound