- can call start()/execute() manually regardless of the execution status

- added clear() method to functionObjectList. It also gets called by ~Time().
  This should destroy function objects before anything else gets
  destroyed (eg, objectRegistry).

- make functionObjectList mutable so it can change behind our back

- added class OSHA1stream for a stream-based calculation method
- dictionary gets digest() method
- dictionaryEntry tweak: avoid trailing space after dictionary keyword