Check C source dependencies in needs_compile
Add test for C dependencies
Fix 'make build_plt'

The dialyzer --add_to_plt call was not specifying the proper
rebar plt to add diameter to.
Merge pull request #293 from liskin/port-deps

Check C source dependencies in needs_compile
Minor follow-up fixes for #293
Merge pull request #360 from tuncer/pr293-follow-up

Minor follow-up fixes for #293
Merge pull request #355 from tuncer/fix-make_build_plt

Fix 'make build_plt'