zap trailing whitespace

another memcmp -> got_object_id_cmp

use got_object_id_cmp instad of memcmp where possible in object_parse.c ok stsp@

typo in comment it serializes the struct got_imsg_tree_entry, not tree_object. grep aid.

add test coverage for new 'got fetch' default behaviour

got: make fetch default to the work tree's current branch As per stsp's todo item, if invoked in a work tree, make 'got fetch' default to fetching the work tree's current branch instead of the branch pointed to by the remote repository's HEAD. ok stsp@ and op@

add a few TODOs for got patch and gotwebd

got_imsg_commit_object: use struct instead of buffer for id ok stsp@

got_imsg_object: use struct instead of buffer for id ok stsp@

cleanup.sh: use `rm -f' to avoid prompting, packfiles are now read-only ok stsp@

got_imsg_send_remote_ref: use struct instead of buffer for id ok stsp@

got_imsg_send_ref: use struct instead of buffer for id ok stsp@

got_imsg_fetch_ref: use struct instead of buffer for id ok stsp@

got_imsg_fetch_have_ref: use struct instead of buffer for id ok stsp@

gotd, gotadmin: install packfiles and index files as 0444 gotd used 0600 (due to mkstemps(3)), gotadmin 0644; change it to 0444 since packfiles shouldn't change once created. Mirrors what git does. ok stsp@