Things to do:

* Move enso.ui.events to enso.events, and have the InputManager be a
  subclass of this package.

* Consider moving all or part of enso.ui.graphics into enso.graphics,
  because they're not necessarily specific to UI code.

* enso.ui.quasimode.charmaps mentions windows vkCodes; this is
  platform-specific and ideally shouldn't be.  I think this goes back
  to some big issue we had regarding how to refactor Enso's input
  handling, but I forget what it was.

* the setQuasimodeKey() and setModal() methods in enso.ui.quasimode
  are very odd; see if we can eliminate them.

* Lots of constants are in enso.ui.quasimode.layout that might
  best be moved to enso.config.

* There are some constants in enso.ui.messages.primarywindow
  that we may want to move to enso.config.  Also consider moving
  the styles for document, p, caption tags, etc.

* Consider moving some constants in enso.ui.messages.miniwindows too.

* Consider turning LONGTERM TODOs in source code into TODOs.