bump hash size and add an algo field to got_object_id

rename "sha1" field to "hash" done with X ,x/\.sha1/c/.hash X ,x/->sha1/c/->hash in sam after loading all the C files; except for one manual tweak in hash.c

handle repository format version 1 and objectformat extensions

sha256 packs support

do not hardcode SHA1 digest length

add got_hash_digest_to_str

prepare got_object_parse_tree for sha256

opaquify sorted_ids

fix grouping in commit traversal

backout 4f73a04b63 "Remove unnecessary sched_yield(2)" this made tog regress hang in an infinite loop, reported by naddy. Remove unnecessary sched_yield(2). Re-applies commit 6b8a2b8fcd99c4365b1aa9513c0f0149beac2491 which was reverted in commit 82954512f323c8a2d4f89d51be1e6b0f707b6c3a because at the time the change broke the 'search' feature. Quick testing suggests search is now working fine, so let's try again.

do not hardcode digest length (cont)

bubble up the hash algorithm

don't hardcode digest length when parsing packed trees ok stsp@

add a comment to remind us to switch back to malloc() while here also fix the function name in the error message, spotted by stsp.

zap double #include <limits.h>; spotted by Thomas Adam

adjust GOT_PACKIDX_NAMELEN for sha256 pack files ok stsp@

fix ref parsing for sha256 ok stsp@

add an algo field to struct got_packidx ok tobhe@, stsp@

add an algo field to struct got_pack Future work on sha256 will need the current hashing algorithm at hand. ok tobhe@, stsp@

add got_hash_digest{,_string}_length() These will be very much useful in the near future.

ensure we properly zero got_object_id structs ok tobeh@

bump version number

CHANGES for 0.101

use proper type for got_imsg_enumerated_tree ok stsp@

use proper type for got_imsg_enumerated_commit ok stsp@