- fixes and feedback from @gfanti and @amiller
- addresses #1049
- minor refactoring
- two global child stems with fixed mapping between parent and
child stem
- allow child stems which don't support dandelion
- only allow outbound connections to be stems
- adjust stems if opening/closing outbound connections (should
allow partial dandelion functionality when not enough outbound
connections are available instead of breaking)
- more exception handling
- only use outbound connections for stems
(thanks to @amillter for info)
- don't create stems if config disabled
- addresses #1049
