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

(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.

Dynamically configure websocket service port, don't attempt htmlterm embed if no such service enabled.

Use FlashPolicy section of services.ini if available, don't attempt to embed if no socket policy server enabled.