Cleanup releasers + builders when interrupted

When receiving a keyboard interrupt (SIGINT) the releaser cleanup
is now called, and the builder is in turn cleaned up.
use wercker instead of travis-ci to enable full test harness

Before this commit: We use travis-ci (ubuntu vm) to run
just the unit tests. We cannot run functional tests on
travis-ci due to lack of platform support.

After this commit: Run the full dockerized test harness on
http://wercker.com to run `hacking/runtests.sh`, which runs
all the unit and functional tests on el5, el6, and f20 to
assert supportability on all the pythons 2.4 through 3.x.

Sample test runs are at:
https://app.wercker.com/#buildstep/5346d0054daac943370042c7
https://app.wercker.com/#buildstep/5346d9914daac94337005096

At the above link...

1. Click **run the docker test suite** in browser to show log
2. Scroll all the way through to see the verbose output and
   summary at bottom.

Note: `hacking/runtests.sh` exits non-zero if any test fails
on any of the platforms.

Wercker docs are online at http://devcenter.wercker.com/#
propagate docs to docker public registry

Add URL of upstream tito repo to HACKING, then
symlink HACKING as README.md in each Dockerfile dir.

Why?

If a README.md exists in same dir as Dockerfile (incl. symlink),
and it's set up as a
[trusted build](https://index.docker.io/help/docs/#trustedbuilds),
then index.docker.io automatically shows the readme on the info
page of the trusted build.
ignored virtualenv and intellij related directories
added rpmbuild output to an error raised by tito to easier the error's cause analysis
Merge pull request #118 from venth/rpmbuild-errors

added rpmbuild output to an error raised by tito to easier the error's cause analysis
Merge pull request #116 from domcleal/cleanup

Cleanup releasers + builders when interrupted
Merge pull request #120 from jumanjiman/wercker

use wercker instead of travis-ci to enable full test harness
Merge pull request #121 from jumanjiman/hacking

propagate docs to docker public registry