Prevent tinymce's html cleaner from cleaning up picker attributes

TinyMCE post processes 'a' and 'img' html elements, removing or altering custom attributes that we use for the pickers. It does that in 2 occasions:

• On content insertion. That is, when you're working in a rich text field and have selected a document/image via the link/image pickers and you press ok
• On loading of the content (when opening the document for editing)

I've added 2 methods that reconfigure the cleaner: 
enablePickerAnchorAttributes and enablePickerImgAttributes. They register our custom attributes for the 'a' and 'img' elements into tinymce's cleaner rules so they are preserved.
 
This tickets is about fixing 2 issues: # For the link picker we must set the attribute 'href' to the value 'http://'. But tinymce is changing this to 'http://localhost' 

1. When loading content, our re-confifguration hasn't occurred yet. Tinymce strips the 'a' and 'img' elements of their 'href' and 'src' attributes respectively; these are required attrs for the pickers to work.

 
Result is that we can pick a document/image and insert it in a rich text field, but after saving the document and reloading it they disappear.