Reorganize Makefile:
- Add dialyzer options to perform more checks
- Add more dialyzer related targets update-dialyzer-baseline,
  and update-dialyzer-nospec-bazeline
- Exclude ".eunit" dir from ctags and etags targets
- Add "rebar" and "rebar.git" targets
- Exclude Lager from eunit-core, eunit-thrift, eqc, proper, and
  triq targets