Bump version to 0.9.3-SNAPSHOT
Add more checking on deploy's credentials

Now that Deploy is a separate module, it is useful to check
whether credentials are supplied for the given target.
Include old repo for 0.12.5-dbuild and 0.13.3-dbuild
Split DeployTarget, so that creds can be directly supplied.

Besides specifying a DeployTarget, which contains a reference
to a credentials file, it is also now possible to use a
DeployInfo, which embeds the needed credentials directly.
Merge pull request #138 from cunei/wip-mix-fix-4

A few minor changes