Revision 190335

o Adding support for <executions/>, which means multiple runs of the same goal/set-of-goals with different configs.
o Adding @phase declarations for those mojos that seem to be part of the main build, just for completeness
o Added two ITs, to test that <executions/> doesn't mess up the normal operation, and to test multi-execution for a goal.

Should resolve: MNG-172.