Added connect(..., encoder=None) parameter allowing connections from decoded origins to newly created non-decoded terminations.  Mostly useful for creating inhibitoury gates by specifying encoders=-10
Fixed bug in stats.runner that stopped running models with different parameter settings
Fixed default pstc for buffers in spa2 to match spa
Added routed thalamus rules in spa2
Added flow configuration to spa2 models, to allow setting cortex-cortex associations rather than just via basal ganglia