Currently the codesign_patched_binary method may be called many
times for the same file when installing a keg.
This removes the calls to codesign_patched_binary from os/mac/keg
and adds a single call to the relocate_dynamic_linkage and
fix_dynamic_linkage methods in extend/os/mac/keg_relocate
to speed up keg installation.
94ef9a4b7a