[Visualpython-users] Fix for Mac

Mirko Bordignon recompiled the Boost libraries on OSX 10.5 and verified 
that VPython then works on both OSX 10.5 and OSX 10.6. He's not sure 
whether it will work on OSX 10.4. There is now available a VPython 5.22 
installer at vpython.org based on his libraries.

Many thanks to Mirko for his prompt response to the problem!

Bruce Sherwood