Added spin boxes, elwin done, conv and fury work in progress

Refs #10626
Fix new spin boxes for conv fit

Refs #10626
Range and preview spectrum selectors on IDA

Refs #10626
Add plot legend to IDR Transmission

Refs #10626
Only change the UI file when needed

Refs #10626
Merge branch 'master' into feature/10626_better_preview_plots_in_indirect_ui

Refs #10626
Add plot legends to Indirect Data Analysis

Refs #10626
Add validation to single fit options

Refs #10626
Better error handling for preview plot updating

Refs #10626
Disable spectra spin boxes by default

Refs #10626
Remove fit curve in MSD fit when changing spectra

Refs #10626
Add better previews to Elwin

Refs #10626
Fix size of elwin UI preview options

Refs #10626
Merge branch 'master' into feature/10626_better_preview_plots_in_indirect_ui

Conflicts:
	Code/Mantid/MantidQt/CustomInterfaces/src/ConvFit.cpp
	Code/Mantid/MantidQt/CustomInterfaces/src/FuryFit.cpp

Refs #10626
Tidy up Fury and Conv fit

Refs #10626
Merge branch 'feature/10626_better_preview_plots_in_indirect_ui' into develop