Correct update for repo.or.cz

Update for repo.or.cz

Add support for salsa.debian.org

Revert "Add support for pinning git.notmuchmail.org"

Add support for pinning git.notmuchmail.org

Don't leave ../ in $SHARE in git configuration; make pin-existing-git match pinned-git here

Revert "This doesn't work because ls-remote doesn't have a --config :("

This doesn't work because ls-remote doesn't have a --config :(

Maybe fix for Travis

Maybe fix for Travis by grepping for another string

Always use /usr/bin/git; fix the $SELF/$SHARE lookup

When given 0 args, exec git with 0 args instead of 1 empty argument

exit immediately if $SHARE is empty to avoid hanging later

Use travis_retry

Maybe fix git.kernel.org cert (point to AddTrust root instead)