Add sublime_lib.view.extract_selector (which is similar to view.extract_scope but better)
Auto-complete scope names according to TextMate's naming conventions

URL: https://manual.macromates.com/en/language_grammars#naming_conventions

Additionally:
- Add "meta.value.yaml-tmlanguage" scopes to YAML Syntax Def's keys
- Add "contentName" to base key completions

Note:
``{ characters": ".", "selector": "source.yaml-tmlanguage" }``
should be added to the "auto_complete_triggers" setting for best usability.