Revision 187639

o Removed dependency on plexus-container-artifact, using nested DefaultPlexusContainer instances instead for plugin isolation.
o Moved marmalade support dependencies out of maven-core, since they can be supported on demand now
o changed the ordering of the ant and assembly plugins, to show that the classloader (plugin param) bug is fixed.
o added a method in PluginDescriptor which is similar to o.a.m.model.Plugin.getId() (I think that's the method; it's the one that results in a key of 'g:a')
o moved wagon-ssh dependency into maven-core, since there is a new issue related to nested containers and wagons which are introduced as plugin dependencies. This should be solved using a mechanism similar to plugin-manager for wagon-manager impl in future anyway