- Split current usage of CXXFLAGS into the conventional CPPFLAGS CXXFLAGS and LDFLAGS
- Split current usage of CFLAGS into the conventional CPPFLAGS CFLAGS and LDFLAGS
- This restores 'make whatever CXXFLAGS=-g' which stopped working during
the recently added suppport for out of source builds.
- LDFLAGS is currently empty, but is there for future use