Merge pull request #16 from jacopen/master

Fix typo
Download remote archives when they are missing and required
Remove Ruby 1.9.2 from supported versions
Delete creating releases from READE.me
Bump BOSH director and other gems
Add `bosh_common` and `blobstore_client` to the Gemfile to use gems on Github

To avoid an error in `bundle install`.
Add installing bundler for rvmsudo
Fix gen-stemcell to support new stemcell-builder