Made some improvements to git-annex's plumbing level commands today. Added
new lookupkey and examinekey commands. Also expanded the things that
`git annex find` can report about files. Among other things, the elusive
hash directory locations can now be looked up, which IIRC a few people have
asked for a way to do.

Also did some work on the linux standalone tarball and OSX app. Both now
include man pages, and it's also now possible to just unpack it and symlink
git-annex into ~/bin or similar to add it to PATH.
