Standardize MOJOs on SimpleDateFormat for timestampFormat

[jgeorgeson]

I found it quite confusing to have a common parameter name shared between MOJOs being implemented in different ways. I prefer the SimpleDateFormat and you already have a utility class that can be called uniformly across MOJOs. I will be submitting a PR to accomplish the following:

1. Update CreateMojo to use Utils.createTimestamp()
2. Check for usage of java.text.MessageFormat value in timestampFormat and warn of it's deprecation while regex parsing out the format for backwards-compatibility
3. Update all the IT projects except basic-it so that the warning and backwards-compatibility are validated.