Redirect to profile edit form after assigning editor (and do not save upfront)

This is needed to complete exportables support. From #624018-135: Exportables and Features support for WYSIWYG 7.x:

Currently, when the main wysiwyg form is submitted, a record is created for each text format, even if the values are entirely empty. So e.g. if the form is submitted and later a module is enabled that provides a default WYSIWYG configuration for one of the existing text formats, the new default will already be overridden.

Proposed implementation: convert wysiwyg overview form to emulate e.g. the fields admin form for a content type.

• Above are shown existing profiles with links to edit, delete, etc.
• Below is a row of form elements to add a new profile. Elements:
  • "Text format" (select list of existing text formats that have no profile yet)
  • "Editor" (select list of installed editors)
• Submitting the form for a new profile brings up the existing profile editing form

Even if this was created by Sun, I suggest we close this as "won't fix" or outdated.