Renaming class in change detection

[vicb]

@mhevery, what do you think of the following changes:

Record<H> -> Change<H>
WatchRecord<H> -> ??
MapChangeRecord<K, V> -> MapChanges<K, V>
MapKeyValue<K, V> -> MapChangeRecord<K, V>
CollectionChangeRecord<V> -> CollectionChanges<V>
CollectionChangeItem<V> -> CollectionChangeRecord<V>

The main reason for the change is to conform to the observe package terminology. I also find this better suited.

[mhevery]

Overall I think these are good suggestions and we should go ahead and do them.

Record and WatchRecord are essentially the same thing, just one is on fields and the other is on evaluated functions. So I think it should have similar naming. (Long term I think we want to merge them)

I am thinking about Record -> Change I am wondering about the fact that Record is both the Record as well as Change It is change when it is being reported, but it is just record from the point of view of change detection. Wondering if we could better capture that.