Unchecked allocations on the paths a controller's message reaches #174

These sites use an allocation's result unchecked (main e66e103). At all but supervisor.c:1785, a refused allocation makes the daemon write or read through NULL, or lose the old array, as the tables of #88 did. src/verbs.c (verbs_receive, reply) has the same defect. The pull request that names this issue fixes only that file.

• src/lv2.c:430-431 lv2_param_info, src/supervisor.c:1803 sup_instance_verb (ledger PHD_LEDGER_REPLACE): resp_code does strncmp(NULL, ...) (supervisor.c:130) when sup_call answers with sup_resp and sup_resp's strdup fails.
• src/names.h: names_add.
• src/supervisor.c: meta_of, tail_add, conn_add, worker_new, worker_attach, chain_uris, format_words, sup_host_setting, pend_add, ledger_verb, add, put, sup_worker_list, sup_chain_get, chain_update, chain_world_found, sup_chain.
• src/pins.c: pin_build, pin_put, record, pins_set_layout.
• src/descriptors.c: descriptors_add.
• src/proc.c: proc_have_binary, manifest_names, proc_find_lv2_bundle.
• src/lv2.c: manifest_files.
• src/json.c, which parses a scan's descriptor: jnew, jparse_bare.
• src/supervisor.c:1785 sup_instance_verb: when its strdup of the line fails, the daemon answers a valid message with -902.