merge: delay debug messages for merge actions Show messages at a point where the actions have been sorted, thus preparing for backout of 760c0d67ce5e. This makes manifestmerge more of a silent operation, just like 'copies' is. Indent 'preserving' messages to make them subordinate to the action logging so they fit in the new context. (The 'preserving' messages are quite redundant and could also be removed completely.)