Merges branch 'ponychicken-backup'.

* going from s3 to file target wasn't working
* use 'local' in the config instead of a file: url, for the local target, so it is not path-specific
* break out the S3 fields since users can't be expected to know how to form a URL
* use boto to generate a list of S3 hosts
* use boto to validate that the user input for s3 is valid
* fix lots of html errors in the backup admin

Also clarify a comment and remove an unneeded type check

Backup location and maximum age can now be configured in the admin panel.
For now only S3 is supported, but adding other duplicity supported backends should be straightforward.

see https://discourse.mailinabox.email/t/bug-present-for-ages/694/3

Some users report munin is broken because munin and munin-node disagree about the name of the machine. I think this occurs if hostname (used by munin-node) reports a different name than PRIMARY_HOSTNAME (which we put in the munin config).

Hard-code PRIMARY_HOSTNAME in munin-node.conf.

Fixes #474.
See https://discourse.mailinabox.email/t/404-not-found-on-admin-munin/623/24.

dont run network checks during upgrades since this is a bad reason to block an upgrade from going through

forgot a 'continue' statement
see 216acb0e
fixes #497

fix occ upgrade to not bail when occ returns 'ownCloud is already latest version' exit code 3, see #496

v0.12c

remove live dependency on Sourceforge

everything was already on master

use a temporary mirror for roundcube while Sourceforge is recovering from an outage https://twitter.com/sfnet_ops/status/622171668497076224

hard-code pyzor sevice URL because 'pyzor discover' is failing because Sourceforge is offline, fixes #496

use a temporary mirror for roundcube while Sourceforge is recovering from an outage https://twitter.com/sfnet_ops/status/622171668497076224

hard-code pyzor sevice URL because 'pyzor discover' is failing because Sourceforge is offline, fixes #496

Add TLSA record for SSL connections.