Package versioning scheme.

[OmegaMetor]

This will be a package versioning scheme to allow for multiple versions of the same package to coexist with a standardized scheme.

This will allow for a version to be passed in after an @. If it cannot find this version, it will fail. If it can find the version, it will use it. If no version is specified, it will use the latest version available.

[OmegaMetor]

I think I'm gonna do this by having versionable packages be folders with a separate json for each version.