Rename key used from "cache" to something bootup specific

[jwlrs]

Considering that bootup may live alongside other code that wants to use localStorage, it would be a good idea to use a less generic name for your key on localStorage.setItem, in order to avoid accidental collisions. Maybe "bootupjs.cache" or something.

Otherwise, great idea!

[djmc]

Good point! Maybe being able to specify what the key is will also allow a bit of control if even that is a collision for whatever reason.