Debian: Updates from the 0.9.24 release, including patch refresh, not checked in at the time.

Cherry-picked out of
https://launchpad.net/~i2p.packages/+archive/ubuntu/i2p/+files/i2p_0.9.24-1ubuntu1.debian.tar.xz
The files in http://deb.i2p2.no/pool/main/i/i2p/i2p_0.9.24-1~deb8u+1.debian.tar.xz
are somewhat different.
Note that some files out of that tarball are apparently older than what is in our debian/
directory and were not copied over.
Some of the changes may be for Ubuntu and will not work for Debian.
Kytv may have had a local debian/ directory for Ubuntu builds that was not checked in anywhere.
Untested. Another patch refresh for 0.9.25 may be required.
To be fixed up after the 0.9.25 release.