Fix for HTML 5 validation prevnting form submission on certain pages

This resolves #61 

I have turned off the HTML 5 form validation on the forms which make use of TinyMCE by specifying a "novalidate" flag in the form create settings. HTML 5 form validation is only useful in browsers that support it and it now falls back to server-side validation which is more than sufficient. Due to the way that TinyMCE (and similar plugins such as CKEditor) manipulate the textarea it causes them to be hidden. When the HTML 5 form validation kicks in certain browsers don't like the fact they can't focus the invalid field.

I have also removed the existing TinyMCE plugin and added the [CakeDC TinyMCE Plugin](https://github.com/CakeDC/TinyMCE) via Composer which should make it easier to update in the future. This was just a useful upgrade and not directly related to resolving the problem.