OC6 - Add possibility to include another apps dir automaticaly

For now, when we install OC from git, we have to DL both core and apps repo separately.

You setup OC, then edit you config.php to enable your 'multi-apps' directory.
To ease a bit the process, i propose to allow to put a "apps2" symlink  that will be automatically recognized by OC as another "apps" dir.

What do you think?