Merge branch 'VE-353' into VE-549
VE-549: parameter normalizing for category and label keys.
VE-549: actually, we only need to normalize labels.
VE-549: track tools.
VE-549: can't track by label, track by static name instead.
VE-549: add save dialog tracking.
VE-549: move label normalization to else block.
VE-549: simplify label normalizing logic.
Merge pull request #1926 from Wikia/VE-549

VE-549: add tracking for the VisualEditor toolbar