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

This is the beginning of support for naddy's suggestion to break this out similar to git. More code to come from stsp. ok stsp@

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 tracey

ok tracey