Merge pull request #117 from quintonm/master

misc bug fixes
sonar URL changed (since we went to single module)
sonar URL changed (since we went to single module)
Merge branch 'master' of https://github.com/p6spy/p6spy
Revert "ignore null values when setting options"

This reverts commit 8b30bc222a77665152763b2b00d294a04664ac50.
Issue #124 - Add the maven enforcer plugin to fail build with friendly error message if Java 7 is not used.