Use labs() instead of opts() to support R v3.1.0
Merge pull request #128 from eleostech/master

Use labs() instead of opts() to support R v3.1.0
Use verbatim to keep error messages intact 

This keeps GitHub's org processor from turning -- into — and making the error hard to read or search for
Merge pull request #129 from pnc/patch-1

Use verbatim to keep error messages intact
Remove non-core modules
Dialyzer -Wunmatched_returns fixes