Add 'qc' Makefile target and simplify rebar.config

* debug_info is enabled by default with updated rebar binary
* configure qc_opts and add 'qc' Makefile target
Fix R16 compatibility (stop using pmod)
Merge pull request #17 from tuncer/build-system

Add 'qc' Makefile target and simplify rebar.config
Merge pull request #19 from tuncer/r16

Fix R16 compatibility (stop using pmod)