Removed app\AppKernel.

* Changed app\App to extend Silex\Application.
* Created app_dev.php.
* Use environment parameter to determine twig caching
* Use debug parameter in error handling
Check whether current branch is up to date in manner that allows for remote branch to not exist.
Merge branch 'hotfix/v0.2.1'
Merge tag 'v0.2.1' into develop

Fixed failure if deployment is tracking remote branch that does not exist.
Don't return current tag if on a branch.
Merge branch 'hotfix/0.2.2'
Merge tag 'v0.2.2' into develop

Don't return current tag if on a branch.
Created pages to view all deployments, all deployment releases and all release upgrades.