Adding a new additional validation rule in the gii-crud generator enforcing the expected format.

removed unused code $patterns

useTablePefix => useTablePrefix

use tableprefix on gii model generator

typo fix

Fixes #1263: Fixed the issue that Gii and Debug modules might be affected by incompatible asset manager configuration

without this the form does not allow choosing a different connection id

if component id is different from 'db'

Refactored ActiveRecord::find() so that find(null) will also return an ActiveRecord instance instead of ActiveQuery.