docs about response

Fixes #1586: `QueryBuilder::buildLikeCondition()` will now escape special characters and use percentage characters by default

csrf docs added

Fixes #1681: Added support for automatically adjusting the "for" attribute of label generated by `ActiveField::label()`

mail component in basic app

Merge branch 'debug_module_improvements' of github.com:Ragazzo/yii2 into Ragazzo-debug_module_improvements

Conflicts:
	extensions/yii/debug/panels/DbPanel.php

Updated git-workflow.md to remove a false link

Refactored tests.

Replaced link to gitref.org to try.github.com as gitref.org is down.

enhance Inflector  helper with ascii function

* upstream:
  Fixed CSRF token masking issue.
  improved error message of calling invalid scope method.
  Fixed repo URL
  Fixes #1650: Added Connection::pdoClass.
  code style fix.
  added changelog
  codestyle fix
  improved checkIntegrity method
  Modified extension guidlines
  fix sphinx command signature
  fixed bug with forgotten param, fixed behavior for one table integrity
  fixed sequence reset
  added postgresql features to reset seq/check integrity