Have the option to have finer dependencies

[brianmoose]

Currently we specify dependencies by specifying just the recipe name. If the recipe has multiple build configs then all configs must pass to move on to the next stage.
For example, for chigger we have a single recipe with build configs for linux and mac and a merge that depends on that recipe. Both linux and mac tests must pass for the merge to happen.

For the package builder we would like a different dependency chain. We would have a "Package build" recipe that has multiple build configs, one for each platform that we build the package on. Then have a "Package create" recipe (with the same build configs) that depends on "Package build". It would be cool to have the dependency only on the same build config. For example, once the build is done for ubuntu 14, then we could immediately move on to creating it without waiting for all the other builds to finish and pass.

The current way around this would be to have different recipes for each platform (ie build-ubuntu14.cfg, create-ubuntu14.cfg, etc).

@milljm If you want this functionality right now you can create all the different recipes.