How to change Migration Table name and use defined prefix.

Comparing #2 with #4

Content

[...]
```php
// Command Map
'commandMap'=>array(
'migrate'=>array(
  'class'=>'system.cli.commands.MigrateCommand','   'migrationPath'=>'application.migrations',   'migrationTable'=>'{{migration_history}}',   'connectionID'=>'db',    'templateFile'=>'application.migrations.template',
),
),
```
[...]