First round work on a Qt version of calibrator program.  This now:
   * reads energies from setup file and loads these to the list view
   * inputs the exposure files from a selection using a file browser
   * Need to make the folowing work add/remove rows from the table,
clear energies and exposures removing these from the table & adjusting
the image view accordingly.
   * Have added in the filters on bottom left panel.  Visible min and
max are now adjusting the image levels and Low and High cutoff & pair
filters are now masking image file as appropriate.
   * usign pyqtgraph for the image display.  This allows moving the
image around and zooming in and out to allow working on the whole image.
This was a problem which needed much more work with the Wx code and was
probably the main reason to switch to Qt.
   * Have implemented initial Find Crystals which uses same search code
as the calibrator does.  It currently finds regions along the top row of
the detector, which is what was happening with the wx version.  Fixing
one should fix the other.
   * Added Add ROI to the context menu.  This now adds an ROI to the
image.  It is meant for user driven ROI creation.
   * The current ROI implementation: add one from menu or use Find
Crystals create ROIs which can be modified (location & size).  For now
this does not feed back fully into the program to define the rectangle
regions that will be used to do calibration.  Need to add in this

Now most of the building blocks are in place.  Need to go through a
round of cleanup & implement some features more fully before working
through the actual calibration part of the program.