Added helper thread

Interfacers can use helper threads to handle http requests so the main
loop can continue without being held up by timeouts. An interval is set
by the interfacer (via settings or defaults) and a url string is
maintained by the interfacer, The helper just actions a "urlstring" at
each "interval" if "pause" is not set and puts it in a queue back to the
interfacer (queue should only ever be 1 item max)
Merge pull request #121 from otherWIP/weather

Added helper thread