fixing warnings on Mavericks about in-class initialisation of static data members
fixing more warnings on Mavericks about initialisation of static data members within classes
fixing warning about implicit hiding of method in base class by derived method with same name but different signature.
fixed use of deprecated finite method, fixed unused variable warning
fixing missing flag in Makefile for compilation of unit tests that was causing failure on MacOS X Mavericks. Piranha now builds without warnings on MacOS and passes all unit tests and regression tests.