always initialize threads
rosthreadL tidy loggings
rosgobject: move logging here
tests: variable frequency
move low level wrappers here

* ServicThread, ServiceGObject
* SubscriberGObject
* Add a ParameterThread/ParameterGObject etc
parameter server access needs locking
move wrapper widgets into wrapper.py
Split and implement class heirarchy for wrappers

* TopicWidgets (for showing topics)
* ServiceWidget (for maintaining widget sensitivity and state)
* PublishWidgets (for publishing thigs)
* ParameterWidgets (for mirroring parameter server values)
* Start/KillNodeWidgets (for launching nodes)
tests: update to new API
tests: move treeviews here
tests: add a glade demo