Changed __config to react to all of clang's currently documented has_feature flags, and renamed _LIBCPP_MOVE to _LIBCPP_HAS_NO_RVALUE_REFERENCES to be more consistent with the rest of the libc++'s flags, and with clang's nomenclature.

llvm-svn: 113086

llvm-svn: 111750

llvm-svn: 103516

llvm-svn: 103490