fix(api): serve until the "acceptconnections" job

This fixes a bug that I encountered when using socket activation with
docker 0.8.1. When running the first `docker run` it would return:
"create: command not found".

The root cause was the socket activation code path was starting to
listen before the "initserver" job had finished. This meant that the
"create" handler hand't been registered yet leading to the command not
found error.

In log format it looks like this:

```
[/var/lib/docker|9d2e78e9] +job initserver()
2014/03/01 04:05:35 Listening for HTTP on fd ()
[/var/lib/docker|0d71c177] +job create()
create: command not found
[/var/lib/docker|0d71c177] -job create()
[/var/lib/docker|0d71c177] +job acceptconnections()
[/var/lib/docker|0d71c177] -job initserver() = OK (0)
```

To fix the issue select on the activationLock and block until the
"acceptconnections" job has ran.

Docker-DCO-1.1-Signed-off-by: Brandon Philips <brandon.philips@coreos.com> (github: philips)
bump go to 1.2.1 in the Dockerfile

Docker-DCO-1.1-Signed-off-by: Cristian Staretu <cristian.staretu@gmail.com> (github: unclejack)
runtime: Fix unique constraint error checks

The sqlite3 version in fedora (3.8) returns a different error string in the unique constraints
failure case than the one in hack/ (3.7). This updates the check to detect both, fixing
one integration check failure on Fedora.

Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
aufs: Skip tests if aufs not supported

This makes it possible to pass the rest of the testsuite without aufs in the kernel.

Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
Merge pull request #4420 from unclejack/bump_to_go_1.2.1

Bump Go to 1.2.1 in the Dockerfile
Merge pull request #4200 from alexlarsson/fix-fedora-tests

Fix fedora tests
Merge pull request #4398 from philips/fix-socket-activation

fix(api): serve until the "acceptconnections" job