php: Fix support for JPEG and PNG over GD.

Set an explicit path to the location of libjpeg for version 5.4 and an explicit
path to libjpeg _and_ libpng for version 5.3.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
zabbix20: Update to version 2.0.6.

Release notes for this version and 2.0.5:

http://www.zabbix.com/rn2.0.6.php
http://www.zabbix.com/rn2.0.5.php

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
chromium/updater: Remove workaround for <= v26.

We no longer need the tar.bz2 archives, so let's remove the switch.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
chromium/updater: Fall back to previous version.

This is especially annoying for the dev channel, as it happens quite frequently
that tarballs are unavailable. So if fetching the latest version doesn't work,
try the second latest version.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
chromium/updater: Fetch more previous versions.

Omahaproxy has an URL which lists a history of the published versions, which
allows to not only go back one versions, but several. Now it is ensured, that we
always have the latest _available_ version in sources.nix.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
chromium/updater: Avoid downgrading versions.

Previously we have just checked for equality. When going back in history, that
way if the history is somewhat out-of-sync, we could end up "updating" to an
older version, which we definitely don't want.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
chromium: Update beta and dev release channels.

The following new versions were introduced:

beta: 28.0.1500.45 - builds fine and tested
dev:  29.0.1521.3  - builds fine and tested

Although the version from the dev release channel isn't the latest found on
omahaproxy but it's the latest one, that actually has tarballs available.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>