Commit 25.
- New view.get() API for finding parent/child views by type.
- Renamed view._hlp to view.hlp - public API to find contextual helpers/params.
- New and improved tag and view hierarchy navigation APIs, including
view.childTags() and tag.childTags() for finding descendant tags
(optionally filtered by tagName).
- New tag.flow boolean property on tags. If true, ignored by tag hierarchy
navigation APIs.
- New ~root helper in templates to access the top-level (root) data from nested
contexts.
- view.renderContent() now automatically uses the current data context and
parentView

- Includes fixes for #32 #179