- updates how filtering is done on the various FGPositioned query functions - both spatial and ident-based.
- updates the KLN-89b / DCLGPS code to use FGPositioned for all Navaid/Airport queries.
me:
Add few include directives in globals.cxx to avoid such MSVC warning messages :
deletion of pointer to incomplete type 'FGAirportList'; no destructor called
deletion of pointer to incomplete type 'FGNavList'; no destructor called
deletion of pointer to incomplete type 'FGTACANList'; no destructor called
deletion of pointer to incomplete type 'FGFixList'; no destructor called
Here's part 2 - converting FGFix (the simplest one) to be both heap-based and inherit FGPositioned. One minor benefit from this is replacing some dangerous code in FGFixList which used to return the address of an iterator member ('&it->second'). To keep the diff a sensible size, I'm not updating the callers to use the richer FGPositioned types - i.e replacing separate lat/lon handling with SGGeod. I will make those cleanups, but in future patches.
