Add new busy event to paraviewweb pipeline manager, new pv protocols, update documentation.
This issue was created automatically from an original Mantis Issue. Further discussion may take place here.
Add event to pvweb pipeline manager that will indicate the busy status of the pipeline. Also added new rpc protocols to allow custom filters and sources to be specified for applications that use the web pipeline manager, as well as to allow loading an arbitrary list of plugins on web application startup. Added documentation of new event and protocols.