Ck editor images

[Monica-Wood]

This enables users to both add images via URL and style them (Add caption, Alt Text, positioning and sizing).

For the image styling to work, you need to disable htmlpurifier in its current form, as it doesn't support HTML5. Suggest moving to the newer htmlpurifier with HTML5 definitions library: https://github.com/xemlock/htmlpurifier-html5 as ezyang has refused to support html5

For pawtucket to style the images correctly, the ck-content class needs to be added to blocks with ckeditor content.

Also a few extra clean ups, like using a separator, adding highlighting and special characters. Turned on grouping, to make the editor tidier. Resizable was missing from the htmlFormHelper.

If it helps. This is the editor toolbar config I have been using:

wysiwyg_editor_toolbar = {
        formatting = [Undo, Redo, -, Source, -, Header, Bold, Italic, Underline, Strike, Subscript, Superscript, RemoveFormat, -],
        insert = [Link, Image, Video, Table, Highlight, Blockquote, SpecialCharacters, -],
        lists = [BulletedList, NumberedList, Outdent, Indent]
}

I didn't change it in this commit, not knowing how many out there use the default outlay, but feel free to update it if you think it's a better structure.

Future development:

• Add ability to upload images using the editor (storing in a directory in media)
• Update purifier to use HTML definitions so this can be used with purifier still on.

[Monica-Wood]

Since this pull request, I have done more work on the ck-editor plugin. I will leave this as is for the moment, but will be creating another one or two pull requests over the coming days. One is for the HTMLPurifier to accept more HTML5 elements and the other is one that includes a wider variety of ck-editor elements.