Altered:
- Round 2 of trying to get the optimization to work.  It is VERY close.
Might be right, but might not be.  Needs further testing to be sure.
Altered:
- After testing, it appears to reproduce the old code identically.  It
takes about 80 ms to do the full computation.
Altered:
- Still tweaking the code.  I somehow added a big inefficiency that I
don't understand.  Working on it.
Altered:
- By switching away from using the QVector implementation and just using
double * (aside from initialization) I have reduced the time to 20 ms.
This is a 3-4 times improvement.  Will do further testing before
finalizing the changes.
Altered:
- Cleaned up all the code that I changed so that it is consistent and
easy to read.
- Removed all the timing code.
- Made sure to put back any pieces I commented out to help with testing.
Merge pull request #841 from acquaman/Issue713Attempt2

Pull Request for Issue713 attempt2: REIXS Improve XES image processing