[Adium-devl] Let's abandon disk images

[Sam]

I have a sort of different idea:

- Put a file inside of the disk image that can identify it as ours.
(If it exists at Adium.app's level, then we need to copy ourself.)

- When Adium launches, check to see if that file exists. If so, do the
whole dialogue thing, copy Adium (somehow figure out copying
permissions, too)

-  Launch Adium from the new location, **Passing an argument** that
tells it to eject the disk image. The old Adium exits. (no strange
scripts needed!)

-  When the new Adium launches, it gets that argument and cleans up
the disk image, etc.

- Tada!