Refactored /finger/thimbl to handle issues more easily

* Created a new controller ThimblController to handle the finger connection
  .plan parsing and ThimblDocument preparation code and pick the elements
  to print
* Form code is now in thimbl_inputForm.html
* Improving code documentation in ThimblDocument::FromJSON
* Fixes T128: Fatal error: Call to a member function AddToBlacklist() on null