Clarify the semantics and code of account transactions report a bit.
In the web account register view, emphasise the "historical balance" vs
"running total" distinction; show it as a label for the chart as well,
to reduce confusion.
- the web UI has been streamlined; edit form, raw & entries views dropped
- we now remember whether sidebar is open or closed
- better help dialog
- keyboard shortcuts are now available
- better add form
- more bootstrap styling
- static file cleanups
- report filtering fixes
- upgrade jquery to 2.1.1, bootstrap to 3.1.1, drop select2, add typeahead, cookie, hotkeys
- clarify debug helpers a little
- refactoring
