Fix build on OS X

OS X's linker seems to be more strict than Linux's and requires you
actually tell it to link against the moar library.  Re-use the
previously Windows specific @moarimplib@ to add that flag.
Ignore OS X shared libraries
Remove unneeded Windows tweak
Add DESTDIR to m-install
Merge pull request #238 from Benabik/nom

Fix build on OS X