Packaging|ubuntu, issue #601: Allow packaging prerm to do its job
Display containers logs in case of build failure
following the 'go vet' suggestions.
following 'go vet' in utils pkg.
Improve last log output
Make sure the ID is displayed usgin run -d
Ignore stderr while doing tests
URL schemes of both Registry and Index are now consistent
Fix a nil dereference in buildfile_test.go

The test runtime object wasn't properly initialized.
Always return the correct test image.

And not a *random* one from its history.
Merge pull request #1032 from andrewsmedina/govet

following the 'go vet' suggestions for the docker package.
do not merge hostname from image
Tentative support for independent registries
Skip certificate check (don't error out on self-signed certs)
Ignore 'registry not found' when pushing on independent registries
Rolled back of previous commit (skip cert verification)
Remove https prefix from registry
Reenable writeflusher for pull
Several fixes and updates to make this work with latest changes in master
Allow push by ID when using a custom registry