[Mac] Roundup of fixes for building on mac

[kudaba]

Two of these changes are to get makefiles working properly on mac, the third was just nice since then I didn't have to specify which standard library to use (which might have changed between xcode versions).

For the linker one, it turns out -l isn't super portable, but ld is fully capable of taking in objects, archive and dynamic object (so,dynlib) by path directly without using -l.