Add CakeDC TinyMCE plugin to Composer
Replace existing TinyMCE with CakeDC TinyMCE

The existing TinyMCE plugin is used in several places, remove the existing
usage and make use of the new CakeDC plugin which is pulled in via
Composer making it easier to update.

- Include CakeDC TinyMCE plugin in bootstrap and setup a global config
- Add server side validation when rejecting a member's details
- Add default validation message to MemberEmail fields
- Remove old TinyMCE helper
- Fix bug which prevents members names appearing when using the "E-Mail
  all current members" function
- Fix breadcrumbs which appear on the reject member's details page
- Delete all webroot resources for old TinyMCE plugin
Correct whitepace issues
Merge pull request #63 from NottingHack/bugfix-61

Fix for HTML 5 validation preventing form submission on certain pages