Split stdout stderr for non-tty commands
Add stderr unit test
Make StdCopy works with huge amount of data
Add documentation
Adding more tests around `auth.ResolveAuthConfig`

mostly because I've been failing at getting docker `0.6.2` working with
docker-registry `0.6.0` with regard to login and push.  I suspect there
may be some mismatched expectations between `auth.ResolveAuthConfig` and
`registry.ResolveRepositoryName`, but I haven't done enough research or
experimentation to think it's anything more than user error.  More tests
are good, no?
Fix #1993: add explanation for export restrictions
Replace deprecated upgrading reference to docker-latest.tgz, which hasn't been updated since 0.5.3
Update Gentoo installation documentation now that we're in the portage tree proper

We're officially a first-class Gentoo citizen now, which is very exciting.  Many thanks to @gregkh for helping us get here.

I started just adapting sections of language in this document, and realized several bits needed to just be rewritten entirely to be more clear.
Merge pull request #2004 from kencochrane/master

fix the error message so it is the same as the regex issue #1999
Merge pull request #2001 from tianon/gentoo-tree

Update Gentoo installation documentation now that we're in the portage tree proper
Merge pull request #2000 from tianon/deprecated-docker-latest-tgz

Replace deprecated upgrading reference to docker-latest.tgz, which hasn't been updated since 0.5.3
Enable SSH Agent forwarding in Vagrant VM, so one is able to clone repos from private git repos etc.
Add the X-Docker-Registry header and /v1/_ping endpoint
Remove smart quotes. Add the X-Docker-Token header

Also fix the /layer endpoint, which had incorrect information
Fix Authorization headers
lxc: Allow set_file_cap capability in container

This means you're able to set the bits for capabilities on files
inside the container. This is needed for e.g. many fedora packages
as they use finegrained capabilities rather than setuid binaries.

This is safe as we're not adding capabilities really, since the
container is already allowed to create setuid binaries. Setuid
binaries are strictly more powerful that any capabilities (as root implies
all capabilities).

This doesn't mean the container can *gain* capabilities that it
doesn't already have though. The actual set of caps are strictly
decreasing.
Configured FPM to make /etc/init/docker.conf a config file.
Hint for Remote API doc details in header links
Used tabs for alignment when I should've used spaces. Fixed.
Move run -rm to the cli only