Regenerate project with new Zephir version
Update schema

- Add groups table

- Add group_id to users table
Update models to latest scheme
Fixes and features

- ModelMetaData add getColumns, getColumn methods

- Start writting support for join in QueryBuilder

- another small fixes
Split MetaDataInfo property|column, init property fixes
Implement joins in QueryBuilder (sql part)
Fix ci
Remove oldest c generated code