[Swarm-Support] Issues with gcc 4+

[Steve Railsback]

We're seeing more people posting support questions related to using 
Objective-C Swarm with versions 4.0.0 and higher of the gcc compiler. 
These versions are now the default in new Linux and Mac releases, and 
are incompatible in some ways with the official Swarm 2.2 code.

The two potential problems are:
o Swarm 2.2 itself will not compile with gcc 4+
o Swarm models that run on Windows or older Linux systems will not compile.

We've updated the Swarm wiki to provide help. There are now solutions 
for installing Swarm (an unofficial release of Swarm that compiles in 
gcc 4+) at: http://www.swarm.org/wiki/Swarm:_stable_release
(see: Important Note For Linux/Unix Users on the gcc Compiler)

There are now some hints for getting old Objective-C Swarm code working 
under gcc 4+ on the FAQ at:
http://www.swarm.org/wiki/Swarm_FAQ:Writing_Objective_C

If you've had to fix problems you don't see on the wiki, please post 
them so others can be aware of them.

Thanks especially to Marcus Daniels, Paul Johnson, Bill Northcott, and 
Steve Jackson for dealing with this.

Steve Railsback