Refs #6473. Merge remote-tracking branch 'origin/master' into 6473

Conflicts:
	Code/Mantid/MantidQt/MantidWidgets/CMakeLists.txt
Refs #6473. Changed the way the sequential dialog is opened.
Refs #6473. Pass loading algorithm to the dialog.
Refs #6473. Helper functions to create load algorithm.
Refs #6473. Creating and passing the algorithm to the dialog.
Refs #6473. Refactored dead time correction a bit.

So it now uses the same routines as algorithm creation function.
Refs #6473. Minor fixes in MuonAnalysis.
Refs #6473. Merge branch 'feature/6473_muon_seq_fitting' into develop

Conflicts:
	Code/Mantid/MantidQt/CustomInterfaces/inc/MantidQtCustomInterfaces/MuonAnalysis.h
	Code/Mantid/MantidQt/MantidWidgets/CMakeLists.txt