Housekeeping on ckeditor - no version change

See https://github.com/cdnjs/cdnjs/issues/2578#issuecomment-33577958
for background.

Includes deletions, with approval from @thomasdavis (see
https://github.com/cdnjs/cdnjs/issues/2578#issuecomment-33578755 for
info). Removing samples, extraneous readmes, minifying assets. Appears
to unify the structure of the ckeditor library directory.