* Need a way to run an action when a property changes, but only run it once for the whole. For example, may want to restart apache, but only once despite many config changes being made to satisfy properties. onChange is a poor substitute. * I often seem to want to be able to combine Properties monadically. * --spin needs 4 ssh connections when bootstrapping a new host that does not have the git repo yet. Should be possible to get that down to 1. * Make a way to express that a Property can be reverted (ie, installing a packages reverses to removing it). Then `reverted property` can be used to disable old properties.