[Factory] Remove {username} from named URL factories

[slemeur]

A named factory on Codenvy is attached to a username. We support the various format:

• /f?user={username}&name={factoryname}
• /factory?user={username}&name={factoryname}
  We need to remove the {username} for Che as it will be always {che}.

We can keep the /f?user=che&name={factoryname} but we need to handle that kind of url:

• /f?name={factoryname}
• /factory?name={factoryname}

[skabashnyuk]

Removed /factory/username/factoryname and /factory/factoryname since they wasn't implemented

[skabashnyuk]

Decided to abandon this issue. Since we may be will need user name. We will left fake user "che".