Refs #8534. MuonAnalysis: new functions for calculations.
Refs #8534. MuonAnalysis: plotSelectedItem() using new functions.
Refs #8534. Plotting on Grouping tab using new functions.
Refs #8534. Removed unused functions.
Refs #8534. Fixed auto-update.

Plus make sure group for every run is created when run is loaded.
Refs #8534. Fixed re-plotting.
Refs #8534. More unused functions removed.
Refs #8534. Minor readability improvements.
Refs #8534. Better error handling.
Refs #8534. Minor UI fix.

Problems when updating plot on focusLost(). Plus same signal was
connected twice in different places.