Feature/link aggr capab create remove impl

Implementation of LinkAggregationCapability.createAggregatedInterface(AggregatedInterface aggregatedInterface) and LinkAggregationCapability.removeAggregatedInterface(String aggregatedInterfaceId).
Both methods delegate to an action each.

Such actions have been created in org.opennaas.extensions.router.actionsets.junos, and are part of LinkAggregationActionSet.
- CreateAggregatedInterfaceAction
- RemoveAggregatedInterfaceAction

WARNING: These actions have some limitations the user must be aware of:
- CreateAggregatedInterfaceAction requires interfaces to be aggregated include NO subinterfaces. User must delete existing subinterfaces before trying to use an interface in an aggregation.
- RemoveAggregatedInterfaceAction requires given aggregatedInterfaceId is in the model. User must execute the queue between a creation and a removal, or the removal will fail.

This patch fixes following issues:
http://jira.i2cat.net:8080/browse/OPENNAAS-1332
http://jira.i2cat.net:8080/browse/OPENNAAS-1333
http://jira.i2cat.net:8080/browse/OPENNAAS-1337
http://jira.i2cat.net:8080/browse/OPENNAAS-1338