[new feature] db utils create_table improvements

Today I’ve added to db utils ability to create table similar to Laravel:

db()->utils()->create_table($name, function($table_helper) {
  $table_helper
    ->small_int('actor_id', array('length' => 5, 'unsigned' => true, 'nullable' => false, 'auto_inc' => true))
    ->string('first_name', array('length' => 45, 'nullable' => false))
    ->string('last_name', array('length' => 45, 'nullable' => false))
    ->primary('actor_id')
    ->index('last_name', 'idx_actor_last_name')
    ->option('engine', 'InnoDB')
    ->option('charset', 'utf8')
  ;
});

Full list of supported column types as methods is here:
https://github.com/yfix/yf/blob/master/classes/db/yf_db_utils_helper_create_table.class.php

You can take look at the tests here:
https://github.com/yfix/yf/blob/master/.dev/tests/functional/db/class_db_real_utils_mysql.Test.php#L312