BZ1092148: Don't allow Association objects in BP's which aren't linked at both ends.
BZ1092148: Add "Connecting Objects" section back to the palette.
BZ1090104: generate <bpmn2:signal> elements for ThrowEvents (signals are already generated for other events).
BZ 1166228 - Data Object show list is different for Variables and for Imports
BZ 1128368 - Numerous issues with Assignment editor for custom Service Task
BZ 1165756 -  Ruleflow group editor does not allows sorting of columns
BZ 1130061 - Validating a process in Web Designer containing a Service Task inside Swim Lane complains
Added some initial CMMN classes and stencilset