add some missing libraries to DPADD and fix up some outdated deps

gotsh no longer needs to link to libz and libm

remove dependency of gitwrapper, gotctl, and gotsh on object_parse.c Move some functions from object_parse.c into hash.c. These functions either require hash.c code anyway or contain object ID implementation internals. Add a new file object_qid.c, for got_object_id_queue and got_object_qid. This new file must be linked to virtually every program.

significantly reduce the amount of code linked into gitwrapper By moving got_serve_parse_command() from lib/serve.c into lib/dial.c as got_dial_parse_command(), we can significantly reduce the amount of symbols gitwrapper depends on indirectly. As a downside, gotsh now needs to link to dial.c. But it only uses the same parsing routine, and any other routines in dial.c would likely cause pledge violations in gotsh if used. No functional change.

rename lib/sha1.c to lib/hash.c It will soon grow functions to deal with sha256 too. stsp@ agrees.

fix gotd build Add missing srcs and update got_repo_read_gitconfig() to be consistent with recent changes. ok stsp@

stop installing git-{receive,upload}-pack symlinks to gotsh in ~/bin Having those links in the user's PATH can make our send/fetch regression tests fail. We do want to talk to git-daemon during those tests, and these symlinks can get in the way of that.

allow gotsh(1) to be installed as git-receive-pack and git-upload-pack in $PATH

introduce gotd(8), a Git repository server reachable via ssh(1) This is an initial barebones implementation which provides the absolute minimum of functionality required to serve got(1) and git(1) clients. Basic fetch/send functionality has been tested and seems to work here, but this server is not yet expected to be stable. More testing is welcome. See the man pages for setup instructions. The current design uses one reader and one writer process per repository, which will have to be extended to N readers and N writers in the future. At startup, each process will chroot(2) into its assigned repository. This works because gotd(8) can only be started as root, and will then fork+exec, chroot, and privdrop. At present the parent process runs with the following pledge(2) promises: "stdio rpath wpath cpath proc getpw sendfd recvfd fattr flock unix unveil" The parent is the only process able to modify the repository in a way that becomes visible to Git clients. The parent uses unveil(2) to restrict its view of the filesystem to /tmp and the repositories listed in the configuration file gotd.conf(5). Per-repository chroot(2) processes use "stdio rpath sendfd recvfd". The writer defers to the parent for modifying references in the repository to point at newly uploaded commits. The reader is fine without such help, because Git repositories can be read without having to create any lock-files. gotd(8) requires a dedicated user ID, which should own repositories on the filesystem, and a separate secondary group, which should not have filesystem-level repository access, and must be allowed access to the gotd(8) socket. To obtain Git repository access, users must be members of this secondary group, and must have their login shell set to gotsh(1). gotsh(1) connects to the gotd(8) socket and speaks Git-protocol towards the client on the other end of the SSH connection. gotsh(1) is not an interactive command shell. At present, authenticated clients are granted read/write access to all repositories and all references (except for the "refs/got/" and the "refs/remotes/" namespaces, which are already being protected from modification). While complicated access control mechanism are not a design goal, making it possible to safely offer anonymous Git repository access over ssh(1) is on the road map.