Merge tag 'upstream/0.17.0' into debian/experimental

Upstream version 0.17.0

# gpg: Signature made Mon 01 May 2017 16:54:30 CEST
# gpg:                using RSA key 3667486A326DB2766D255546860DEF3B8F650B79
# gpg: Good signature from "Ximin Luo <infinity0@pwned.gg>" [ultimate]
# gpg:                 aka "Ximin Luo <infinity0@torproject.org>" [ultimate]
# gpg:                 aka "Ximin Luo <infinity0@freenetproject.org>" [ultimate]
# gpg:                 aka "Ximin Luo <infinity0@debian.org>" [ultimate]
# gpg:                 aka "Satoshi Nakamoto (www.bitcoin.org) <satoshin@gmx.com>" [ultimate]