touch: prompt the user for what to do with the revived changeset This patch improves our interface for reviving changesets. This patch makes touch not assume that the user wants to create divergence by default and gives a prompt instead. The prompt is skipped for changeset that have no living successor as no divergence would be created by reviving them anyway. To restore the previous behavior, one should now use the --allowdivergence flag. The prompt looks like: [10] <description> reviving this changeset will create divergence unless you make a duplicate. (a)llow divergence or (d)uplicate the changeset? a In further patches we will want to add one more choice to that prompt, for example having a marker between the old and revived nodes but no divergence displayed on the UI.