Rendering potentially 1000s of nodes can exceed the CPU and memory constraints
of a normal PHP process, as well as the rendering capabilities of browsers.
Set a hard maximum for the renderable nodes, deferring to a "show as list" action
in the main CMS tree. For TreeDropdownField, we don't have the list fallback option,
so ask the user to search for the node title instead.
Also makes both the "node_threshold_total" and "node_threshold_leaf" values configurable
- Removed duplicated content from page-type-templates (was more or less a variation of the content in templates.md)
- Removed built-in page-controls, which was a bit of a dumping ground for unconnected topics.
Moved the majority to page-type-templates
- Removed all recipes from "sitetree" docs, since they were outdated or hacky (like grouping of records, or implementing custom *children() method on subclasses)
- Added pagination, escaping, base_tag, CurrentMember to template docs
- Removed default_parent docs from SiteTree, as this setting doesn't have any effect looking at core
