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