Add optional itemIdToCreate property to Pre-Deployment screen for recovery scenario.

When deploying a site to production (or workflow), I would like to be able to optionally target a specific Item ID in the addItem request.  I would use this to restore a site (or workflow) from a Portal Item backup or Development state, reusing a previous Portal Item ID.  In the SaaS environment, it would allow me to persist the URL to a site even if it were lost or needed to be restored.