Assists in detecting wagon providers brought into the plugin class path via legacy Maven core artifacts (e.g.
maven-core:2.0.6) and excluding them. A plugin should be able to explicitly declare dependencies on specific wagons
for its use. However, the (old) wagons pulled in transitively via legacy Maven core artifacts are usually not
intended as dependencies and more importantly screw up artifact resolution because they would get preferred over the
core wagon versions. This is a hack to provide backward-compat with Maven 2 (MNG-4528, MNG-4561).
- Benjamin Bentmann