Feature requested by naddy. ok naddy, who also suggested some tweaks that will arrive shortly

Known to work against git-daemon and github Git server implementations. Tests by abieber, naddy, jrick, and myself. Man page additions reviewed by Lucas.

This saves an iteration over the entire h->offsets array when opening a pack index which should not contain large offsets in the first place. ok millert@

Make use of this in 'got clone' to persist -R option arguments given on the command line in the cloned repository's got.conf(5) file.

Set fetch-all-branches in the got.conf(5) file created by 'got clone -a' in order to make a future 'got fetch' act like 'got fetch -a' by default.

ok millert

ok tracey

ok tracey