Use tools.mk Makefile

This eliminates a lot of Makefile duplication between repositories.
Eliminate most dialyzer warnings

* Eliminate many warnings
* Remove use of dialyzer ignore file

The majority of the warnings in the ignore file are no longer valid
because we've now put the dependencies in the PLT, and not included
directly in the call to dialyzer.
Update xref ignore file
Update tools.mk
Merge pull request #777 from basho/feature/tools.mk-makefile

tools.mk makefile and dialyzer fixes