Keep menu in sync with relation updates.
Merge pull request #127 from makyo/menu-sync

Uses the update cycle of the topology to keep the menu in sync.

To QA: run with `/:flags:/relationCollections`, add two services, relate them, bump one service up to 100 units, click the relation indicator, and wait for the relation to go bad; menu should reflect this.
    Local charms in sandbox mode.
Merge pull request #128 from frankban/zip-sandbox-improvements

Local charms in sandbox mode.

Complete the functionality.
Improve the way zip archives are parsed.

QA: deploy local charms in sandbox mode.