Replace Makefile with gulp
Generate install.rdf and chrome.manifest
Cleanup .gitignore
Reformat changelog
Add gulp release task
Make `require` more like Node.js

- Add support for `module.exports`.
- Add support for npm modules in `require()`. Note the following differences
  with Node’s `require()` though:
  - Only `require(path)` is supported, not `require.resolve()` or related
    `module` properties etc.
  - Absolute paths (`/foo/bar.js`) are not supported.
  - Only JavaScript files may be required (not JSON files, for example). Paths
    must not end with `.js`.

Moreover:

- `module.onShutdown(handler)` is used instead of
  `require('unloader').unloader.add(handler)`.
- bootstrap.coffee has been cleaned up. I had a lot of help from looking at
  <https://github.com/adblockplus/buildtools/blob/7a305df14bf3d26ff559f06082b87ff7cff4b3b8/bootstrap.js.tmpl>
- `extension/packages/` has been renamed to the more Node-style
  `extension/lib/`.
- The huffman module has become its own repository, and is now `npm install`ed.
Configure coffeelint and fix lint errors
Always remove build/ and build from scratch

This is way simpler. The only reason not to do it is speed. But for this project
there was no difference!
Add unit tests infrastructure
Remove legacy tests dir
Merge branch 'develop' of github.com:akhodakivskiy/VimFx into develop