DEBUG: getting the trace-back is useful when dev/debug the app
ENH: Builder components: warn if 'constant update' param field looks dynamic

- print a note during compile if it seems like dynamic updates are intended
  but the update flag was set to 'Constant'
- all tests pass (testApp probably has the only relevant ones)
- works on all Builder demos
- maybe integrate with ComponentDialogs instead or as well?
  nice to provide a suggestion immediately, but could be annoying