Failed deployments should be retried on server restart

Currently, AS7 does not attempt to redeploy failed deployments upon restart. This makes for a suboptimal UX, since users now have to rename their .failed marker to .dodeploy every time they want to retry it upon restart, which is a bit of a pain. This is also different from the behavior seen in previous AS releases, which will make it a bit of a surprise for users coming from previous versions.

Additionally, this can be frustrating for other projects that use AS7 (such as TorqueBox) that have alternate means of deployment, and whose users will not necessarily have any knowledge of deployment markers.