Explicitly rebuild gems for stemcell build
Remove all TODOs from codebase

Important ones have been added as real chores/bugs.

Signed-off-by: Colin Humphreys <chumphreys@pivotallabs.com>
cleanup stemcell spec

 * add assets for non-AWS and aws + light contexts
Bosh::Dev:Stemcell knows its AMI ID
rename Bosh::Dev:Stemcell #is_light? to #light?
Bosh::Dev:Stemcell looks for AMI ID in the correct location

 * add DEFAULT_AWS_AMI_REGION
Bosh::Dev::Build can promote assets from pipeline
add .rspec file
stop "puts"ing in specs
ci:publish_artifacts uses Bosh::Dev::Build#promote_artifacts
Removed redundant stemcell filename building
Reduce code duplication in bosh-dev Pipeline
Replaced s3cmd with Fog::Storage in bosh-dev Pipeline
Log when we upload or download to the pipeline
Mock pipeline in BatHelper and CandidateArtifacts
Backup blobstore based on database content
Removed list() operation from blobstore clients
TarGzipper can optionally copy files before archiving

* This gets around the problem with logs being written as they are being
  tarred.
Backup of logs and task_logs now copy_first when targzipping.

 * Prevents nasty tar errors when logs are written while targzipping.
Include all CompiledPackage in the blobstore backup