stuff to get `got log -p' working

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@

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@

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

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

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

avoid copying reused deltas to delta cache file; copy from pack file instead ok op@

got send: show server error Print the error message reported by the remote server when failing to update a branch (for e.g. because of a server-side check.) Reported by gonzalo@, with help and ok stsp@.

convert got_pack' filesize to off_t; ok stsp@

move declaration of got_privsep_child out of got_lib_privsep.h This declaration is the only reason why got_lib_privsep.h must be included in order to use got_lib_repository.h. Moving this declaration will allow for cleaning up unnecessary includes of got_lib_privsep.h.

ensure got patch respects x-bit perms for new files Reported by stsp on IRC: got patch failed to set the x-bit for a new file despite got diff recording mode 755. Parse got and git diffs for this data and set file modes accordingly. Tweaked with hint from op. ok stsp@