#8 Respect CXXFLAGS and LDFLAGS.

[dirtyepic @ gentoo]

1. don't overwrite CXXFLAGS and LDFLAGS. These are variables for the user to set.
2. use CXXFLAGS when linking. some flags can change linker behaviour by implying linking options. you should always include CFLAGS/CXXFLAGS when linking.

[Death Knight®]

Merged at svn r363.
Thanks for pointing out.