Split install script up

[cmsj]

I think it might be interesting/useful to split install.sh into at least two scripts, an installer, and a separate script adds a volume (or all volumes except /) to the keychain, so users can add additional volumes later (or in my case, I wanted to build the tool myself rather than download it). The separate helper script could be called unlock and could potentially grow features like listing/removing volume entries, if that's reasonably possible with the underlying keychain tools.

[jridgewell]

Sure. I'd also love it if we moved away from a bash script... 😄