Sometimes users would get confused because an option they were looking
for was not mentioned on a subcommand's man page, and they had not
noticed that the main git-annex man page had a list of common options.
This change lets each subcommand mention the common options, similarly
to how the matching options are handled.
This commit was sponsored by Svenne Krap on Patreon.
* When annex objects are received into git repositories, their checksums are
verified then too.
* To get the old, faster, behavior of not verifying checksums, set
annex.verify=false, or remote.<name>.annex-verify=false.
* setkey, rekey: These commands also now verify that the provided file
matches the key, unless annex.verify=false.
* reinject: Already verified content; this can now be disabled by
setting annex.verify=false.
recvkey and reinject already did verification, so removed now duplicate
code from them. fsck still does its own verification, which is ok since it
does not use getViaTmp, so verification doesn't happen twice when using fsck
--from.
