Allow users to "Force Upgrade" when they've changed a project they've launched from a project share

[njhale]

When a user changes a project they've launched with a project share, they are blocked from upgrading to new revisions of the share.

We want to change this so that when a project diverges from the share, users can "Force Upgrade" their project to the latest revision.

Requirements

• When a user changes a project, they are presented with a "Force Upgrade" button on their project config page
• Performing a force upgrade will upgrade the project to the latest revision, dropping any changes they've made
• A new revision of the related share does not need to be available to "Force Upgrade". The only requirement is that the project has diverged from the last revision it was successfully launched at or upgraded to