- handling special keys better for commands requiring a character
- r can operate on selection
- fixed: t moves back if character not found
- +/-/_ via extension of moveByLines motion

Closes #1264

Closes #1268

Closes #1274

No full measurement is needed, since most of the time the longest line will
be scrolled out of view, and we're only interested in its length.

Issue #1275

Closes #1129

Closes #1271

Issue #1262

Closes #1267

Closes #1264

Closes #1265

- Link to external jsonlint.js (don't want dependencies in repo if
  I can help it)

- Use a single demo file (prevent demo/ from becoming a huge mess)

- Make whitespace and newlines conform to other files, fix linter errors

This way, we don't have to shuffle coordinate systems.

Closes #1255

Closes #1252

Closes #1254

I don't think anyone is using it anymore, and it was a kludge to begin with.

- gj/gk for moveByDisplayLines motion, allows vertical movement within
wrapped lines
- :noh[lsearch] is now an ex-command
- new ex-commands can be defined through api, using
CodeMirror.Vim.defineEx()
- :{number} should now move to line with {number} on the gutter
- parseKeyString now also accepts keys like <Space> (in addition to
<C-{Key}>)