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.

It will soon grow functions to deal with sha256 too. stsp@ agrees.

after got_object_id_hex was introduced and used in error.c, the building of delta, deltify and path failed due to missing symbols. Spotted by stsp and tracey, ok stsp