Replace missing work, add es6, fix copied text bug.

[cutandpastey]

This PR:

• Re-integrates work lost by https://github.com/guardian/scribe-plugin-noting/pull/49 (and my terrible merge).
• Adds es6 support.
• Removes Plumber from build.
• Adds a release script grabbed from scribe.
• Fixes https://github.com/guardian/scribe-plugin-noting/issues/53 which was re-introduced by reset-note-barriers refactoring.
• Adds errorHandle which adds debug information to thrown errors.
• Adds .jshintrc to project

  QA

• Be sure to check that un-noting part of a note does not add any erroneous text:

[robinedman]

:+1: