Add ob_end_clean to a few places that need it in order for the admin to ...

...work correctly when gzip is enabled. I noticed in a few places there seems to be something that is put in the output buffer when certain functions are being called. I've gone through the CMS and found, what I believe, are all the places that this is happening and put some ob_end_clean calls in there in order to make the gzip compression work again.