Make it so demo pages point at relative project so they can work

It can be hard to work on demo pages within a relative project (`../canjs`) because they are not copied over to the `canjs.com` folder.

When something like `2.2@../canjs` is used on the command line, the demo page paths should reflect this change.

This will mean that one should always run without the `2.2@../canjs` before publishing (which is a good idea anyway).