set error_reporting for tests
made gridview plural rule compatible with ICU version < 4.8

issue #1072
added unit test to verify storing of null values

http://www.yiiframework.com/forum/index.php/topic/48359-inserting-nulls/page__view__findpost__p__226019
fixed unit tests for cubrid and postgresql

both do not support unsigned integers
refactored Component::off().