Bug fix: when a rename is pure the script would still delete the
target file instead of leaving it alone. We really only need to handle
integrates where the content of the file changes - pure name changes
in the source are not an issue for us since the whole point of the
script is not to propagate them.
This change ensures that in the case of a file branched due to a
rename, the branch and the associated delete are both reverted.
Also took out the -I flag to integ, which is archaic now.