script/install-xcode is a self-contained script that installs Xcode.

Apple credentials are accepted over stdin.  Using curl and perl's
`HTML::Tree`, they are validated against https://appleid.apple.com/.

Assuming they check out, support for assistive devices is enabled
(this requires sudo.) Using Applescript to script the UI, the App
Store is opened and Xcode is installed.

This version is incomplete, in that the CLI tools are not installed.
Allow prompting for credentials.
Try extrating some applescript methods.

I fear current my 10.7 env isn't quite compatible, bouncing into 10.8
to test..