Parser` and `XMLElement` instances.
:boom: Breaking changes
- `XMLElement`'s `handle` method is renamed to `iter_from`
- The `parse` function has been removed in favour of the new `Parser` class; use
`Parser(stream).iter_from(handler)` instead of `parse(stream, handler)`
:rocket: Added
- `XMLElement` now has a `text` property to walk through all children and gather texts
regardless of the tags
- `XMLElement` new `return_from` method can be used when there are no items yielded by
the handler
- PyPy support
:bug: Fixes
- An exception is now raised when a node is accessed out of order; this avoids
inconsistent behaviors in some cases, and replaces the obscure `No handle to use`
exception in other cases
:memo: Documentation
- Add changelog file