Modified:
-clean up widgets, renaming and structuring for added clarity
-tabbed REIXSXESImageInterpolationABEditor layout to make space for
additional controls needed for second curve fitting
Modified:
Moved "Apply to Scans" option from a QToolMenu to an "Apply" tab.
Modified:
Finalized REIXSXESImageInterpolationABEditor layout using tabs to
minimize control widget space and maximize plot size.
Used better words
ADDED:
Second set of coltrols and methods to REIXSXESImageInterpolationAB and
REIXSXESImageInterpolationABEditor to allow the second curve to be
configured.

REMOVED:
uses to of shiftPosition*_ in favour of correlation*CenterPx_ - should
be easier to use, will have to test this concept on users though.

TODO:
-Add the seconf fitting range and fit curve to the plot within
REIXSXESImageInterpolationABEditor
-Test regorously
Merge branch 'Issue845' of github.com:acquaman/acquaman into Issue845
ADDED:
Second curveSmoother variable and
REIXSXESImageInterpolationAB::setCorrelation2Smoothingto() method to
allow each curve to have a different smoothing applied.

MODIFIED:
computeShiftMap() to store a local copy of the last shift map and added
REIXSXESImageInterpolationAB::shiftValuesAt() getter to allow the editor
to access the shift map.

ADDED:
onCorrelation2CenterBoxChanged() to properly hand two correlation
regions. And REIXSXESImageInterpolationABEditorShift1Model and
REIXSXESImageInterpolationABEditorShift2Model helper classes to provide
plotting data for both correlation regions and the shift map.
MODIFIED:
REIXSXESImageInterpolationAB::computeShiftMap(), fixed bug that resulted
in garbage shift maps, that was revealed by new shift map visualizer in
REIXSXESImageInterpolationABEditor.
Code optimizations.
Code cleanup
Modified:
- REIXSXESImageInterpolationAB::shiftValuesAt() now ensures that cahced
vaules are valid before returning shift map values.

- Removed unused variales and methods, code cleanup

ADDED:
- line edits for manual entry (copy-paste) of shift curves
- Colour coded UI elements for shift curves
Modified:
REIXSXESImageInterpolationAB::shiftValuesAt(int i) to return doubles
instead of ints, so that the actual, sub-pixel shift map can be properly
visualized.
Cleanup:
Removed commented out code blocks
ADDED:
```REIXSXESImageInterpolationABEditor::onShift1LineEdited()``` and
connected to line edit to enable manual shift entry for curve 1
FIXED:
in ```REIXSXESImageInterpolationAB::computeCachedValues()```:

-bug in shifting algorithm: by truncating each shift map value before
multiplying by the interpolation level, sub-pixel shifting wasn't
happening and interpolating the image was a complete waste.

-reversed the shifting algorithm so that each pixel in the shifted image
grabs one pixel value from the interpolated image - as determined by the
shift value at the point - instead of placing each pixel from the
interpolated image into a pixel in the shifted image, which results in
over/under filled pixels. I don't understand how Robert's code ever
worked doing it the latter way.
CLEANUP:
Remove commented out code
MODIFIED:
Tweak plot colors for maximum visability against bone color map
MODIFIED:

-Make the new REIXSXESImageInterpolationAB the default AB for XES scans.
Fixed merge conflicts.
Merge pull request #910 from acquaman/Issue845

Pull Request for Issue845: XES Image Interpolation AB