Refs #6101. First pass at the qtassistant setup.

Missing all autogenerated code and lots of information.
Refs #6101. Adding option to return versions of algorithms as well.
Refs #6101. Make a link even more relative.
Refs #6101. Preparing for more files being autogenerated.
Refs #6101. Moving to autogenerated help for the algorithms.
Refs #6101. Splitting QHPfile into a separate python file for reuse.
Refs #6101. Autogenerate fit function index.
Refs #6101. Small cleanup of CMakeLists
Refs #6101. Moved to new python api
Refs #6101. Added script to write individual algorithm pages.
Re #6101. Added cmake log if qtassistant stuff isn't found.
Re #6101. Create output directory if it doesn't exist.
Re #6101. QTassistant finally building out of source.
Re #6101. Added stub version of the fit function pages.
Merge branch '6101_qtassistant_pilot'