[MENFORCER-182]
  - Added documentation for WARN/ERROR
    Patch applied by Mirko Friedenhagen


git-svn-id: https://svn.apache.org/repos/asf/maven/enforcer/trunk@1561846 13f79535-47bb-0310-9956-ffa450edef68
[MENFORCER-174]
  - Added banDistributionManagement rule.
- Cleanedup code.
- Enhanced docs.