STRBUF_ALLOCA_FIT() macro
strbuf_json_boolean()
All HTTP RESTful responses are JSON, not HTTP

Even error responses (typically code 403)
Refactor MeshMS conversation list

Use an iterator structure, not recursion, to traverse the binary tree of
conversations
rhizome_http.h
meshms.h

Rename exposed MeshMS types and functions by adding "meshms_" prefix

Check binary tree integrity during meshms_free_conversations()
Refactor sqlite_retry_state into rhizome_list_cursor
Implement HTTP GET /restful/meshms/<SID>/conversationlist.json
Refactor MeshMS message-list code to use iterator
Fix bug in Base64 encoding, trailing pad characters
Implement HTTP GET /restful/meshms/<SID>/<SID>/messagelist.json
Refactor MeshMS ply-reading functions

Rename functions to use _prev instead of _next to mean reading
"backwards" ie, from newest to oldest, aka, from higher offsets
to lower offsets
Improve MeshMS RESTful HTTP requests

Include local (my) and remote (their) SIDs in JSON responses for
conversationlist.json and messagelist.json, so that the same JSON
structures can be used in future for non-SID-specific queries.

Refactor MeshMS message iterator, rename "sender" and "recipient" fields
to "my" and "their", for consistency with the rest of the MeshMS source
code, and because "sender" and "recipient" are properties that apply to
a single message or single ply, not to a message thread (conversation).
Refactor rhizomehttp MeshMS message list test

New function add_messages() to use in fixture

Improve existing test case by adding more ACKs and messages
Implement HTTP GET /restful/meshms/<SID>/<SID>/newsince/<token>/messagelist.json

Two new test cases
Refactor to rename "Rhizome HTTP server" to "HTTPD server"

Move HTTPD start/stop/dispatch logic from rhizome_httpd.c into new
httpd.c

Rename config.debug.httpd -> config.debug.http_server
Rename config.debug.rhizome_httpd -> config.debug.httpd
Rename config.debug.rhizome_nohttptx -> config.debug.nohttptx
Rename "rhizome_http.h" to "httpd.h"
Create rhizome_restful.c, meshms_restful.c

Move code from rhizome_http.c into rhizome_restful.c and
meshms_restful.c
Implement HTTP POST /restful/meshms/<SID>/<SID>/sendmessage

Rename struct meshms_ply fields from "buffer" to "record" for
consistency with comment terminology
Remove unused MeshMS record type constant