Updated AP

Set up AP to follow NAV2 radio courses;
Lateral and vertical ILS/GS is working (on NAV1 only);
CPL button on MCP switches between NAV1, NAV2 and FMS;
MCP displays "NAV1," "NAV2" or "FMS";
Updated AP dialog to allow switching and display of NAV source;
Added 20 sec turn anticipation for route manager;