Makefile.in: Don't depend on a phony target for bin/fluidity
Makefile.in: Don't depend on a phony target for bin/fluidity

Rather than depending on fluidity_library, which means bin/fluidity
will be linked every time make is called, depend directly on
lib/libfluidity.a.

FluidityProject/multifluids,FluidityProject/multifluids,FluidityProject/multifluids,FluidityProject/multifluids