Missing features

[guaraqe]

• Redeploy with elections available (adds a new binary)
• Add a scope (unit only / subunits) to elections
• Add a scope to forum threads (unit only / subunits)
• Make most of the information in a unit visible to members of subunits
• Create announcements, which appear in the main page and link to a thread in the post. It will have a scope too.
• Add a page link to elections so we can send them to people
• Decide which actions result in an e-mail (like elections and announcements) and which result in a periodic e-mail sending.