Add pidfile option to the golang implementation

This is required to handle docker-registry with startproc.
Merge pull request #35 from flavio/golang_impl_add_pidfile

Add pidfile option to the golang implementation
Added more information about configuration
Re-organized the README a little bit. Running from a container is now the default way for deploying locally.
Update README.md
Merge pull request #37 from jamtur01/readcfg

Added more information about configuration
Fixed typo
Merge pull request #38 from jamtur01/typo

Fixed typo
registry image name is now docker-registry (was registry)
Update README.md
Merge pull request #41 from looztra/patch-1

registry image name is now docker-registry (was registry)
fix build process
Merge pull request #42 from slnovak/master

fix build process
Replace NotImplemented with NotImplementedError
Merge pull request #43 from marsam/master

Replace NotImplemented with NotImplementedError
Fixed IOError errors when pushing
Merge branch 'master' of github.com:dotcloud/docker-registry
Bumped version to 0.5.5
Add 'how to setup user accounts' to README.md
Added HTTP caching policies (helpful to when behind a CDN)