SideBySide2: Fix truncated long lines

CM3 needs a call to refresh() after setHeight to get the horizontal
width correct for any lines longer than the window width.

Change-Id: I608264d71c98829c2f39d9acef12445088591bbb
Fix the RelatedChanges panel to load all tabs at the same time.

Also refactored the code to remove some of the boilerplate logic.

Change-Id: Id213645547d1124d98ae0f46707f76d528373842
Merge "Fix the RelatedChanges panel to load all tabs at the same time."
Merge "SideBySide2: Fix truncated long lines"