Add AJAX report load

Problem/Motivation

Forena currently provides integration with the CTOOLS module to allow reports to be displayed
in modals, but does not provide other methods of implementing reports that load sub-reports
via ajax. To better facilitate this, I'd like to see the ability to add use-ajax classes to links and have
those links call the forena ajax loader in such a way that any of the normal ajax commands designed
to replace HTML could be used. Visiting reports/myreport/ajax.replace.myid would return an ajax
command that would replace the id myid with html content that is the forena report. All of the
appropriate variations of drupal and/or ctools ajax commands should be supported.

Proposed resolution

Change the primary forena ajax provider to allow replacement of the

Remaining tasks

1. Write code and tests in d8 branch
2. Backport to drupal 7
3. Document in both branches