pothos-gui: EvalGraphBlock cache the type strings as well
pothos-gui: GraphDraw updateEnabledActions in showEvent
pothos-gui: continued tweaks to widget selection
pothos-gui: topology engine commitUpdate tracks changes
pothos-gui: added default types and colors to the map
pothos-gui: make connection text clickable
pothos-gui: updated handlepaste for sig/slots + graph widgets
pothos-gui: TopologyEngine reset signature on clear() topology
pothos-gui: added double click handler work-around for graph widget
pothos-gui: graph widget forces render on block
pothos-gui: a new block eval cache implementation

this implementation is aware of non-critical changes
so that it can apply only the minimal changes
pothos-gui: created gui affinity zone for widget blocks
pothos-gui: eval deal with some edge cases
Merge branch 'block_eval_cache'
pothos-gui: minor fixes for TopologyEngine cache
pothos: fix syslog listener close lockup

* cant close it in the static-deinit context
* added api call to close if from gui main context
pothos-gui: clear block eval cache on env change
pothos-gui: added GUI affinity zone to menus