Refs #9780 Remove offending line.
re #8708 remove the explicit delete of workspaces before fitting
refs #9797. ThetaIn missing.

ThetaIn missing as input to RRO algorithm. The algorithm tries to determine the ThetaIn, but this won't work correctly if the detectors are also out of alignment. Adding the known ThetaIn fixes the issue.
Merge remote-tracking branch 'origin/feature/9797_fix_data_difference'
Merge remote-tracking branch 'origin/bugfix/9780_workspace_ops_name'
Merge remote-tracking branch 'origin/feature/8708_graph_windows_vanish_on_refitting'
Merge remote-tracking branch 'origin/master' into bugfix/9720_apply_corrections_fails_with_older_files
Refs #9720 Better error message.

Also use more appropriate message buttons.