Linked up several editor functions, cleaned up editor event-handler callbacks.
Undo/redo buttons, help text on both editor and microbe stage,
and microbe naming in editor now work.

NB:
- Microbe name doesn't link to either saving (not yet re-enabled) or species
(which aren't on this branch ...yet)
- Layout files have been added and gitignore changed, these could easily be
temporary or permanent changes in project structure.

See #130
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