update todo

- Merge in all sorts of content I had in sticky notes and my pocket
  notebook and such. (There were plenty of these I couldn't decipher or
  understand, too...)
- Get rid of the frontend/backend file distinction, which was just an
  annoyance.
- Split into bugfixes, internal work, features that should be
  implemented to avoid headaches later on, and other features.
write comments for what needs to be added to the notebook delete function

I didn't actually write it because it will be quite difficult and may be
made easier by the addition of some classes I intend to wrap up some of
the occurrence/entry/event functionality in.
split adding into a db and a ui section

Also rename the additionQueue class to have an initial capital, in
accordance with more typical convention.
head off possible bug with very small notebooks

(It would have added leading zeroes where they didn't belong, in the
bizarre edge case that your notebooks had nine total pages or less.
Always good to be on top of these things, though.)
event class

This both enabled and involved quite a bit of code cleaning and perhaps
a few minor bugs fixed.
bugfix: prevent repositioning 0 or negative event

This is valid to Python because it starts selecting from the end of the
list, and would obviously cause unexpected results.
release copyright on manual; bump version