Include artifactId in messages of DeployMojo#processProject

In "deploy all at once" mode a single project does the heavy lifting for all reactor projects once it is determined that others have already been marked with an instance of the State enum earlier.

As mentioned in a comment on PR #39, if a warning is written to the log or an exception is thrown at this point, the issue can be falsely attributed to the current project, and the real culprit can only be determined by temporarily switching back to eager deploy mode.

It would be nice to display which project is being processed, making this investigation easier.