Merge remote-tracking branch 'origin/bugfix/9033_correct_findpeakbkgd'
Added calculation for fit quality. Refs #8601.

1. Refactored codes;
2. Make wiki more detailed on the new features;
3. Add new features including output the deviation of highest peak and
etc.
Merge branch 'feature/8601_getdetoffsets_more_stat' into develop