Re #6630. qhc file move completed.
Re #6630. Checkpointing refactor of qtassistant file reorg.
Re #6630. More shuffling about of directories for qtassistant.
Re #6630. Changed urls for opening help pages from MantidPlot.
Re #6630. Finished moving files around.
Re #6630. Moving from lxml to minidom.
Re #6630. Refactor minidom stuff.