Implement row reloading

- Implement row (and section) reloading for ASCollectionView and ASTableView (#60).
- Nodes are not reused. Thus reloading a node means swapping the old one with a new one.
- UITableViewRowAnimation is not supported (yet).

Any feedback is appreciated :)
Instead of removing these from the commented-out area, can we include them below so there's an explicit list of supported methods?