fixes #842

- allows checking whether a relation has been populated
- getting a list of relation names that have been populated
- getting all populated relation data

todo:

- [] add phpdoc

made querybuilder condition methods public

* 'master' of github.com:yiisoft/yii2:
  typo
  fixed extension list file location.
  doc fix.
  moved extension list under yiisoft. updated read me.
  updated license information.
  reorganized extension directories.
  Adjusted jui directories.
  moved mutex back from extensions.
  Changed the exit status to normal.
  Specify the exact type of the exception.
  Small typos
  PhpDoc comment
  Missing return statement
  Changed php-diff dependency to use code from master (they haven't tagged changes we need yet)
  Added ability to get all GET, POST, PUT, DELETE or PATCH parameters to Request
  Add batchInsert method to yii\db\Migration
  Fixes #1117: added support to map a single view directory to multiple themed view directories.
  Fixes #1116.

updated read me.

Typos

Missing return statement

Add batchInsert method to yii\db\Migration

sqlite does not seem to allow using boolean values in select query

See the following resources for details:
yiisoft/yii#779
https://bugs.php.net/bug.php?id=33876
http://www.yiiframework.com/forum/index.php/topic/32334-boolean-type-with-postgresql/page__view__findpost__p__155647

should be tested for all dbms not only cubrid even if the problem may
not exist in all of them it is good to verify that.

Fixes #1107: if basename of Gii CRUD model and search model are equal than alias is automatically used for search model