The default VERSION of matrix multiply is pthread
Change the debug type to giriutil
Delete the useless releaseMemory member function
Rename the STATISTIC and simplify the descriptions
Share the TraceFilename command line option

This option was defined in the CountSrcLines pass of the Utility
directory, and externed in the Giri.cpp and TracingNoGiri.cpp of the
Giri directory. Thus the order of loading the shared object really
matters. We must firstly load the libdgutility.so and then load the
libgiri.so