Ensured default values, if any, of parameters of overrides, are generated.

Signed-off-by: Dimitar Dobrev <dpldobrev@yahoo.com>

Conflicts:
	src/Generator/Driver.cs
	tests/Basic/Basic.cpp
	tests/Basic/Basic.h
Merge pull request #307 from ddobrev/master

Filled in default values, if any, of private overrides