- Both saved & unsaved
- which supports intellisense in the files

- Define a new extension point `configurationDefaults` for contributing default language specific editor settings

- Extend configuration extension to override default settings for a language
- Update configuration registry with overrides
- Adopt Defaults config model to read default overrides
- Tests

- Introduced an internal boolean property 'overridable'
- Set this property to true while registering configuration
- Support inheriting this property from parent configuration node level

- Use '[...identifiers]` as key

- Register the settings.override setting
- Dynamically update the schema to support intellisense
- Change the language key format to langid or langids separated by comma

# Conflicts:
#	src/vs/languages/html/common/htmlTags.ts