add docs for REST services and Chaining

docs added
Merge pull request #122 from pkit/rest

add docs for REST services and Chaining
vagrant: refactor swift config script

This adds a util function for handling swift configuration.
vagrant: add some comments to swift config script
vagrant: add job chaining middleware to swift conf
vagrant: raise if pipeline target is not found

In `configure_swift.py`, before we were just append to the pipeline list
if the target wasn't found. We should be more conversative: if the
target isn't found, something has gone wrong.
vagrant/configure_swift: add some docstrings
vagrant: add better restart instructions to README
Merge pull request #123 from larsbutler/vagrant-job-chaining

Vagrant: job-chain middleware configuration
refactor RestController slightly

move each GET functionality into it's own method
add new ApiController

the new controller will answer to the `/api/...` urls
using these you can configure even more generic REST interfaces at the expense of losing a container identity.
if you set up `X-Container-Meta-Rest-Endpoint` on the container to a `swift://` url and use the `/api/...` path info
the application or job description will be loaded from that url and executed instead of usual container operation
the original storage-related operations will still be available under `/v1/...` url
Merge pull request #124 from pkit/rest

Improve REST API
fix a strange behavior on some machines

hopefully fixes problems with swift 2.0.0 on some machines, have no idea why it works without that patch here

the main problem is that 404 is returned sometimes from swift 2.0.0 storage backend when we call GET() directly
it looks like the ObjectController class of Swift sometimes uses request and sometimes uses self to resolve account, container or object paths
to make sure that paths are correct everywhere this patch ensures that all ObjectController classes are created with needed paths and container_info is called with proper request objects (as info is cached in the request object environ dictionary)
Merge pull request #127 from pkit/bug_fix

fix erroneous 404s from ApiController, caching related
remove unused functions
fix some test peculiarities

mostly fixed strange json behavior
because tests run python code from strings pyflakes was not detecting proper import usage
Merge pull request #126 from pkit/tests_fix

fix some test peculiarities
Merge pull request #125 from pkit/minor_fixes

remove unused functions
objectquery: factor out sysimage prep

This moves system image preparation out of the `ObjectQueryMiddleware`
and into a util function in called `get_zerovm_sysimage_devices`.
Merge pull request #128 from larsbutler/code-cleanup

Code cleanup