Added:
- Made a file writer for the REIXS XES scan.  I think I found all the
pieces to make it work.  Will require testing on REIXS.
Removed old QDebug calls.
Altered:
- After testing, I had to tweak the file writer and how the data was
accessed before writing to the file.
- I found that the data stream wasn't giving me the correct offset from
::pos() so I kept overwriting the header.  I fixed this by always
writing the header and always seeking to byte 0 before doing any
writing.
Merge pull request #767 from acquaman/Issue697

This has been tested and is good to go now.