Updated source code and OZY/JANUS info.

Added an AGC panel and code to be able to control RX AGC - currently just supports OFF,LONG,SLOW,MEDIUM and FAST.  I will add an additional mode for CUSTOM.

Frank has offered a loan of an OZY/JANUS board set, which I have accepted,  so that I can look at adding support for it.  With the work that Bob (VK4XV) has been doing we should be able to get something working fairly quickly.

This all goes goes to prove what a great group of people we have working on all this.