revise the description of A records on domains: the A record must be present for good deliverability so that the envelope domain resolves, but it doesn't have to resolve to this machine

add link to contributors, remove duplicate "to"s

Changed incomming-email-input to type text

The input type="email" validation won't allow "@example.com", which is needed for catch-all-aliases.

update roundcube version

In the event the first user is an address that we'd normally create as an alias,
we'd generate a loop from the alias to the administrative alias to the first user
account (which was the alias again).

hopefully fixes #186

only hold onto backups for 14 days (not 31) and show when the backups will be deleted in the control panel

Since it runs before the real setup begins, we must make sure that packages are installed.

Also removing bind9-host's installation from system.sh. In 189dd600 I added this so we could use `host`
to aid Docker autoconfiguration. Docker support was since removed but this hadn't gotten removed, which lead me to think it was
normally installed by Ubuntu. It's now installed in `network-checks.sh`.

fixes #180

dns: move the quoting of TXT records to when we write the zone file so that we can display it unquoted in the External DNS instructions

Support more concurrent connections for PHP services

My logs were showing lots of: 
[04-Sep-2014 15:52:41] WARNING: [pool www] server reached pm.max_children setting (5), consider raising it

fixes #175 (hopefully)

fix permissions for owncloud-unlockadmin script

split CardDAV instrctions into a new page and add CalDAV instructions; create nice redirects at /cloud/calendar and /cloud/contacts

Also updating the values for secondary DNS, but we're not set up
for secondary DNS so it won't matter.

see #172

The user might acquire the sources via some means other than a git clone. On Vagrant, the files come in via Vagrant. So test for git before running `git describe`.

Merge branch 'master' of github.com:jkaberg/mailinabox

this will always download the latest ownCloud and upgrade if ownCloud install dir exist, this apphroach allows us to keep existing user plugins. currently not checking if currently installed version is equal to the one we're downloading as I couldn't find a proper solution for that