feat: make the encoding of CJSON objects less tedious and more fun

[rayozzie]

The "f" is for "fun" (or perhaps for "formatted") just as it is in printf.

I have long, long wanted to implement this feature so as to dramatically reduce the number of source lines necessary to create notes (and templates) to just a few. Check it out by starting at the diffs in note.h.

Just to give you a preview...two new methods were added for the same reason that printf was added to clib: it's easier to do things in one 'format string' with multple varargs than to be forced to do a long number of operations (print, print, print, print), one item at a time, as was the case before printf.

notecard.sendRequest(JObjectf("req:hub.set product:com.blues.radnote mode:continuous"));

notecard.sendRequest(JObjectf("req:note.add body:%o file:air.qo", JObjectf("temp:%f", temp)));

The same wonderfulness can be used to add items if you prefer that style.

J *req = notecard.newRequest("hub.set");
JAddf(req, "product:com.blues.radnote mode:continuous outbound:%d sync:true", outboundMins);
notecard.sendRequest(req)

Yes, there are robust tests. No, there is no additional overhead in note-c if you don't choose to use this.