small mistakes in service locator guide.

besides, what is `app\components\SolrService`?

Oracle Schema fix

Fixes #4071: `mail` component renamed to `mailer`, `yii\log\EmailTarget::$mail` renamed to `yii\log\EmailTarget::$mailer`

Revert "Gii `*Search` model generator fix"

Fixes #3101: Improved handling of log target failures

Fixed the route for the User link

OCI createColumn fix

Fixes #3101: Improved handling of log target failures. It will now skip target and log reason instead of going into infinite cycle

Fixes #3568: When the primary query sets `asArray`, it is not respected by the `via` relational query

Fixes #3638: `yii\filters\HttpCache` does not work as expected when session is started before the filter

attempt to fix multiple header issue

fixes #2859

fixes #2988

fixes #3583

fixes #3559

fixes #3893

* consistent-after-save:
  use an AfterSaveEvent class to be consistent
  fixed test break and wrong parameter
  changed updateAttributes to be more simple update
  Ensure consistent behavior in ActiveRecord::afterSave()

Conflicts:
	framework/UPGRADE.md

fixes #3899

fixes #4053