m2e-code-quality/m2e-code-quality#58: Support for Checkstyle 6.x
* Match checkstyle eclipse plugin greaterOrEquals rather than
compatible.
* Use (official?) Checkstyle repo http://eclipse-cs.sf.net/update
Merge pull request #60 from sourcepit/master

m2e-code-quality/m2e-code-quality#58: Support for Checkstyle 6.x