v2.4.0
rename AUTHORS to CONTRIBUTORS and add a few
pass self to get function
pass self to use() function
pass self to trim() function
pass self to del function
pass self to shiftLU function
move closure max to this._max
move closure lengthCalculator to this._lengthCalculator
move closure allowStale to this._allowStale
move closure maxAge to this._maxAge
move closure dispose to this._dispose
move closure cache to this._cache
move closure lruList to this._lruList
move closure mru to this._mru
move closure lru to this._lru
move closure length to this._length
move closure itemCount to this._itemCount
move internal functions out of ctor
move methods onto prototype