Enabled setting two character shortcuts (e.g. jk) to exit insert mode by 1) enabling setting CodeMirror.Vim options in user.behaviours and 2) updating vim.js to latest from https://github.com/marijnh/CodeMirror/blob/master/keymap/vim.js.
Changed set-vim-option to the more sensible set-option, reverted vim.js
Merge branch 'master' of https://github.com/LightTable/Vim into two-char-esc
recompiled files
Merge pull request #35 from JobJob/two-char-esc

Enables setting two character shortcuts (e.g. jk) to exit insert mode