Adds mention of setting up postgresql for owncloud in readme
Limits z-push sync to 3 months

This prevents timeouts when trying to sync very large mailboxes. By
default, z-push attempts to get headers for all messages in a folder.
Redirects naked domain to www

Properly behaving websites should 301 redirect the naked domain.
Uses global roundcube sieve configuration option

The previous behaviour relied on managesieve copying over the
.dovecot.sieve file into the user's directory. I found this to be
particularly fragile. For instance, re-deploying roundcube without
dovecot could overwrite the .dovecot.sieve symlink and break
managesieve.

A better approach is to use the global sieve configuration that
roundcube provides and not mess with dovecot's files directly.
Stops postgresql for tarsnap backup

Data loss will occur if backing up postgresql while it runs. A simple
fix is to stop it during the backup. I've moved the backup to early
morning to reduce possible downtime.

A better approach would be to use pg_dump.
Uses monit to stop/start postgres for tarsnap
Fixes z-push download
Revert "Redirects naked domain to www"

This reverts commit 703d35649227900e2c97e5c09c33cf4dfd69fd16.
Merge pull request #170 from jsravn/master

Some minor tweaks