Provide logs over HTTP, update Bobfile format, fix failing tests

Addresses:

* https://github.com/modcloth/docker-builder/issues/66 - fix parser test failures
* https://github.com/modcloth/docker-builder/issues/8 - add versioning to Bobfiles, update Bobfile format
* https://github.com/modcloth/docker-builder/issues/53 - adding http endpoint for viewing logs per 
* https://github.com/modcloth/docker-builder/issues/27 - indicate how long each build took (via http logs)

Make semi-backwards-incompatible changes to the `Bobfile` format.  Addresses a [change in Go 1.3](http://golang.org/doc/go1.3#map).