Surcease from sending additional header-termination newline (a blank line already appears after the headers.)

(frame.setData() ignores empty parameters, so a separate means of deletion is needed)

Brought back portions of the old sorting method to deal with these cases.
(This update probably needs more testing and review than I've given it.)

todo: score list pagination

Cleanup of async load/post URLs; assume that appendURL is at least / or that it begins and ends with /

added "transparency" mode option to Frame() objects. when enabled, any frame location where the character is undefined will return to the display buffer as being empty, and the next frame down will handle the call.

Removed tbHeader (we're not looking at header.thread_back any more.)

Service ports now included, hopefully minimizing times when sysop will need to mess with extra_ports in modopts

(To do: delete email, change read/unread status.)

If a maxMessages limit has been defined, only report up to this number of messages per sub in the list.