Faster interactive operations: Avoid repeated calls to getWidth()

(need to fix title) - follow on from JAL-2954
2.10.4 introduced a patch to avoid calls to Alignment.getWidth when looping over sequences in the alignment.

Other places where these calls need to be avoided:
Repeated calls in a loop:
Finder.find() - with column selection
JalviewJmolBinding.superposeStructures (twice)
JalviewChimeraBinding
Jalview2XML.loadFromObject
Jalview2XML_V1.loadFromObject
TreeCanvas.colourGroups
AMSAFile.print
AAStructureBindingModel.findSuperposableResidues

Repeated calls where a temporary variable could be used:
ScalePanel.mouseReleased()
SeqPanel.doMouseDraggedDefineMode (applet and desktop)
SeqPanel.editSequence applet/desktop
SeqPanel.scrollToVisible applet/desktop
JalviewLite.selectIn
ScalePanel.mousePressed
ScalePanel.mouseReleased
TCoffeeScoreFile.annotateAlignment
StrucConsensusThread.run