Added DI container implementation.
Turn module and application into DI containers.
Fixed test break.
fixed test break.
Added unit tests.
Refactored container.
refactored code to use Instance::ensure()
Implemented conditional validators (see #2406)
Proposal: GII generate strings for I18N
Fixed typo
Add category for I18N in GII
Fixed overriding default message sources
Added changelog
Changes in GII I18N
added path when script is run from yii2-dev/extensions
DI WIP
Finished refactoring of DI container and service locator.
Merge pull request #2834 from yiisoft/i18n-fix-overriding-default-message-sources

Fixed overriding default message sources
Fixed test break.
More changes in GII I18N