Migrations diff command, creates a new file if you do not find differences

[SongoQ]

Execute the command migrations diff in the case where is no changes creates a new file

./app/console doctrine:migrations:diff

Generated new migration class to "/home/songoq/project/app/DoctrineMigrations/Version20110803142018.php" from schema differences.

cat /home/songoq/project/app/DoctrineMigrations/Version20110803142018.php

...
...
... 

class Version20110803142018 extends AbstractMigration
{
    public function up(Schema $schema)
    {
        // this up() migration is autogenerated, please modify it to your needs
        $this->abortIf($this->connection->getDatabasePlatform()->getName() != "mysql");

    }

    public function down(Schema $schema)
    {
        // this down() migration is autogenerated, please modify it to your needs
        $this->abortIf($this->connection->getDatabasePlatform()->getName() != "mysql");

    }
}

[lenar]

Actually I can see the current behavior being useful. But... I propose this:

• if no actual difference found say "No difference found."
• If --always etc is passed then current behavior.

[stof]

Fixed by #160