Merge branch 'db/remote-builtin' into jk/send-pack

Merge branch 'db/remote-builtin' into jk/send-pack

* db/remote-builtin:
  Reteach builtin-ls-remote to understand remotes
  Build in ls-remote
  Use built-in send-pack.
  Build-in send-pack, with an API for other programs to call.
  Build-in peek-remote, using transport infrastructure.
  Miscellaneous const changes and utilities

Conflicts:

	transport.c