Add feature to 'Open Invisible File...'

[geerlingguy]

See: http://mac.rbytes.net/cat/mac/system-utilities/visibility/

You click the button, and the open dialog pops up. We could have it open into a particular app, maybe, or just let Mac OS X decide the app into which it should open.

(This can be useful, for instance, when I want to open a simple .htaccess file in a webroot somewhere, in TextMate).