this term is resolveable by the php docs when linking types in apidoc

typo fix

Fixes #2629: `Module::controllerPath` is now read only, and all controller classes must be namespaced under `Module::controllerNamespace`

Fixes #2653: Fixed the bug that unsetting an unpopulated AR relation would trigger exception (qiangxue)

This reverts commit 2bb6f135.

fixes #2632

We are now maintaining a fork of pjax:
https://github.com/yiisoft/jquery-pjax

fixes #2623