Allow transactions to be scheduled in the past.

https://github.com/notriddle/budget-envelopes/issues/22
Starting-point prototype for swipe deletion.
Get it to a point where it's actually usable.
Use swipe-to-delete for the paycheck activity's docs.
Bug fix: deleting multiple items in one go.
Increment version number for beta test.
Workaround for some weird rendering bugs in Android.
Make long-click deleting work again.
Make the delayed touch work right.
Increment version number again.
Improve the click feedback.
Add an option to show all the transactions.
I forgot to add these to the commit. I feel dumb.
Bug fix: long-press deleting registered a tap.
Performance improvement recommended by lint.
Finally fixed the notification icons.

I <3 math class and Dr. Isom.
Accessibility: add a contentDescription to widget logo.
Again, mostly for lint's sake, though it helps documentation, too.
Fix up the dialog custom title. Right size on tablets, and remove the redundant layout.
Remove unused strings.