LRU RangeChange contains both addition and truncation at once.
Testing for instantaneous LRU set update.
More efficient and legible LRU set addition.
LruMap notifies of LRU behaviour.
Merge remote-tracking branch 'upstream/master'

Conflicts:
	lru-set.js
Merging lru-set changes.
LruMap store monitoring delayed until addMapChangeListener.
Testing added and modified to use spy.