Fix breakage on missing w-b dump for an arch

The w-b admins may take some time until they have a new architecture all
set up. And until they do generate the buildd.d.o/stats/$arch-all.txt we shouldn't
break on it missing.

Signed-off-by: Joerg Jaspert <joerg@debian.org>
daklib/gpg.py: Raise an error if we see unexpected output from gpg.
daklib/gpg.py: Use timestamp instead of just date.
Add replay protection for uploaded changes files.

Look in signature_history table if the changes was already seen to
prevent re-uploading old changes files.
dak admin: add forget-signature subcommand

The forget-signature command removes the entry for a given file from
the signature_history. This allows reprocessing the file.
Drop unique .changes name requirement and allow ftpteam to forget seen files.
daklib/gpg.py: Handle a few more keywords for invalid or and expired signatures.
daklib/gpg.py: Also handle SIGEXPIRED keyword.
show-deferred: Do not require a valid signature.
daklib/gpg.py: Ignore NOTATION_{NAME,DATA} keywords.
apache.conf-incoming: Grant access to mahler.debian.net

Bug: https://bugs.debian.org/754742
daklib/gpg.py: Ignore SIGEXPIRED and KEYEXPIRED
tanglu: Allow some source-upload types
daklib/checks.py: Add instructions how to get an upload processed again.
daklib/regexes.py: Do not allow colons in filenames.

Colons should not be used anywhere as the epoch part of versions is
not included in the filename.
Only inject processed uploads into signature_history

Uploads that were 'skipped' should not be recorded in
signature_history as they will be repeocessed later.
process-new: Indicate which packages were not include in upload

Show "NOT UPLOADED" besides overrides for packages that were not
included in the upload.
apache.conf-incoming: Grant access to home.mraw.org
export-suite: Add --relative option.
Move canonical incoming.debian.org location

Signed-off-by: Mark Hymers <mhy@debian.org>