Handeling plugin loading in python tracer.

Python tracer did not load plugins when loaded from GUI. This
was because the tracer did not handle any events for plugin loading.

Two new events named LocalPluginLoadedEvent and RemotePluginLoadedEvent
were added and triggered when LocalPlugins and RemotePlugins we
loaded. Handelers for these evens were added in vtkSMPythonTraceObserver
and consequently in smtrace.py.

on_local_plugin_loaded() and on_remote_plugin_loaded() in smtrace.py
write out the corresponding pythong code to the tracer output.

Change-Id: I85942da954e71273ec03a6a3d493965f22d70119
Update visit bridge with pflotran reader that support time series

Change-Id: I0d5433d3c7d78fd01546d9b1e902524850013b86
Merge topic 'pflotran_timeseries' into next

78141ff Update visit bridge with pflotran reader that support time series
Merge topic '0012052-python-trace-load-plugins' into next

72bfe4a Handeling plugin loading in python tracer.
Update VTK to latest origin/master

Change-Id: I78af17ba46fed1fbd27da15132adf08ece299efc
Merge topic 'update_vtk_master' into next

46e95d4 Update VTK to latest origin/master