Nunjucks 4 roadmap / tracking ticket

This issue is a draft and is still being updated

Features

• Support self variable (#164)
• Support loop filtering (#261)
• Support loop controls (e.g. break / continue) (#296)
• Recursive for loops (#416)
• {% block scoped %} syntax (#1118)

Bug fixes

• Make empty variables falsey (#267, #541)
• Fix nested macros and call/caller (#664, #799)
• Cannot reference outer scopes from inside a {% call %} block. (#679)