Blow away old code
Add libvtd as git submodule
Section-based folding for vtd files
<Leader>t opens VTD view window; Q/q quits
Track VTD view using buffer number only

Now I don't have to use the ugly, arbitrary __VTD_VIEW__ name!

I had to switch to :bwipeout instead of :bdelete. The latter is very
inconvenient: it causes bufexists() to return true for the 'deleted' buffer
number, but deletes all the special buffer options I had set.
Elegant s:FillView() implementation

I'd rather use arrays of lines of text, instead of appending strings with manual
newlines.  Not to mention, it's much more elegant to forego the dummy register
entirely, instead of saving and restoring its value!
Placeholder "fill with summary" code
Enable libvtd to be loaded by vim-vtd
Tweak vim-python interface function names

UpdatePython() was wrong; it's really the TrustedSystem we're updating.

Also, now I call EnsurePythonLoaded() every time view.vim is sourced, so python
is always available.
Add Keymap class
Put global setup at top of autoload file
Implement view-object-based API

Everything is now based on two externally-visible functions:

- vtd#view#Enter([view_type]): Enter the view buffer, creating if necessary.  If
  [view_type] is supplied, make sure the buffer has that type.

- vtd#view#Exit(): Exit and destroy the VTD view buffer.

Under the hood, I use the new s:VtdView superclass.
Consistent 2-blank-line spacing between units
Placeholder for 'Summary' and 'Contexts'

Mostly-dummy versions.  However, notice how 'j' is remapped in the 'Summary'
view, but *not* in the 'Contexts' view.
Don't setup mappings in Keymap constructor

It's more useful to be able to construct a list of keymappings in any buffer,
and later on, set all the mappings in bulk.  (This will let me add mappings
valid for *all* View types, e.g., navigational mappings.)
Add API/helper subsection headers
Add navigational keymaps for vtd view
enter() a buffer so display will refresh
Add CyclableOption class

This paves the way for context statuses, which can be cycled among 'include',
'exclude', and 'none'.
Commands & API functions to alter context settings