Two gpg fixes today. The OSX Mtn Lion builds were pulling in a build of gpg
that wanted a gpg-agent to be installed in /usr/local or it wouldn't work.
I had to build my own gpg on OSX to work around this. I am pondering making
the OSX dmg builds pull down the gpg source and build their own binary,
so issues on the build system can't affect it. But would really rather not,
since maintaining your own version of every dependency on every
OS is hard (pity about there still being so many OS's without sane package
management).

On Android, which I have not needed to touch for a month, gpg was built
with --enable-minimal, which turned out to not be necessary and was
limiting the encryption algorythms included, and led to
interoperability problems for some. Fixed that gpg build too.

Also fixed an ugly bug in the webapp when setting up a rsync repository.
It would configure `~/.ssh/authorized_keys` on the server to force
git-annex-shell to be run. Which doesn't work for rsync. I didn't notice
this before because it doesn't affect ssh servers that already have a ssh
setup that allows accessing them w/o a password.

Spent a while working on a bug that can occur in a non-utf8 locale
when using special characters in the directory name of a ssh remote.
I was able to reproduce it, but have not worked out how to fix it; encoding
issues like this are always tricky.

Added something to the walkthrough to help convince people that yes, you
can use tags and branches with git-annex just like with regular git. One of
those things that is so obvious to the developer writing the docs 
that it's hard to realize it will be a point of concern.

Seems like there is a release worth of changes already, so I plan to push
it out tomorrow.
