* new UI for parts support of SWITCH node
* update UI of SWITCH node for parts support
* add server side code of new SWITCH node
* update info document of SWITCH node
* add tests for new SWITCH node features
* add test for too many pending messages & related fixes
* fix handling when msg is undefined
* tabs -> spaces
* fixed meaning of "repair sequence" in SWITCH node docs
* add a note on restricting internally kept messages
* change label and position in menu of "pos. between" rule
* fixed typos (again, sorry)