python-pyblock: Update to version 0.53.

As the SHA256 changed in the meantime and there are only minor changes
between 0.52 and 0.53, I've updated this to the release tarball, which
hopefully won't change anytime soon.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
python-pykickstart: Update to version 1.99.39.

As well as pyblock, the SHA256 changed here as well. Although the
changes between 1.99.32 and 1.99.39 aren't as minor as with pyblock,
this shouldn't have any impact on nixpart so I think it's safe to
upgrade (we'll see later, should we end up with failed tests in nixpart
or <nixos/tests/partition.nix>.

Of course we're now using the release tarball from the repo site here as
well.

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

beta: 30.0.1599.22 -> 30.0.1599.37
dev:  31.0.1612.0  -> 31.0.1626.0 (new patch sandbox_userns_31.patch)

I've rebased the user namespace sandbox patch against current trunk for
the dev version, because it didn't apply anymore.

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