Minor change for QC test results reporting

Report the name and arity of a command for QC test results.
Add callbacks for running statem test with PropEr
Fix norton/lets#8 - impl_destroy/6 is calling a wrong port function.
Fix norton/lets#9 - a typo in lets_output_delete2().
Fix a typo in README.md; "make eqc" should read "make compile-for-eqc".
Merge pull request #11 from tatsuya6502/impl_drv_typo_fix

Impl_drv typo fixes - norton/lets#8 and norton/lets#9
Add Tatsuya Kawano
Fix a typo in doc/overview.edoc; "make eqc" should read "make compile-for-eqc".
Fix a documentation typo in src/lets.erl
Fix rebar configuration to match R16 or newer
Silence compiler warning for Mac OS X clang
Update rebar (2.2.0-61-g97751ec)
Update overview.edoc
Update copyright
Refresh edocs
Correct travis.yml