Fixed the calculation of height for the upload (non AssetUploads) area
so that the save button would show. Took off the min-height, as this
will cause UI issues when there are multiple files open for editing.
1. Add arrows to edit dropdowns
2. Adjust lightened fields so they don't look like input boxes, and fix
rgba colours
3. Add ability to click file names to edit
4. Add feedback when edit button is hovered
5. Add feedback if a file has been opened for editing and shut again
(saved changes, unsaved changes, unchanged)
6. Add ability to open and close all files to edit them all at once
7. Add overall feedback for file uploads, and fix NaN error
8. Fix up area to match design
9. Fix error messages so they fit in the provided space
10. Fix case where a single uploaded file errors
Changed the calculation of the iframe size so it would be the correct
height. Altered the styles of the view details area to match design.
Changed the background color of the title on the file header so it
wouldn't look editable (as recommended by Felipe)
http://open.silverstripe.org/ticket/7046
UploadField would default to one folder only, and wouldn't allow asset
tree traversal. HtmlEditorField MediaForm has this capability, so added
it here in a similar fashion via TreeDropdownField.
Added classes to dropzone when dragging and dropping files. Added
styles to the dropzone when a file could be dropped. Added a clearfloat
mixin to the mixins file.
