Moved MultiMap code around
Remove duplication in MapOps [Breaking change]

findEntryWithKey(p)   => entryFor.matchingKey(p)
findEntryWithValue(p) => entryFor.matchingValue(p)

keyForMinValue        => keyFor.minValue
keyForMinValue        => keyFor.maxValue

valueForMinKey        => valueFor.minKey
valueForMaxKey        => valueFor.maxKey

entryForMinKey        => entryFor.minKey
entryForMaxKey        => entryFor.maxKey
entryForMinValue      => entryFor.minValue
entryForMaxValue      => entryFor.maxValue