{base_interaction.py -> interaction.py}
Subscribe as well to salient events

ie, instances of SalientEvent
Initial support for explicit requirements for actions

Use the new decorator 'workswith' to list the required middleware
(and optionally the modules/nodes required)
Action requirements: minor formatting
Minor fixes to be more resilient when ROS/POCOLIBS are missing

While here, update the syntax for statements lifespan to
match pykb.
Fixed logging levels

The various levels should now be correctly honored.