Fixing removeAllRanges API call.

removeAllRanges does not get any argument.
Use own `EventEmitter`
Use `_.where`
Do not needlessly run formatters when executing `insertHTML` command

The formatters are already run thanks to the `MutationObserver`.
Merge pull request #132 from guardian/oja-insert-html-tidy-up

Do not needlessly run formatters when executing `insertHTML` command
Add path to sanitizer plugin

[ci skip]
Add sanitizer plugin to example

[ci skip]
Tidy up docs
Resolve doc TODO
Add new browser inconsistency re. `insertHTML` command
Wrap lines to 80 cols
Tidy up
Tidy up
Style example editor
Add failing test normalization formatters
Add failing whitespace test
Tidy up
Add sanitize and prepare phases to HTML formatting
Rename prepare phase to normalize
Do not rely on order of object properties