dynamic loading and mach/macosx

[David Sugar]

I have rewritten the dso class for support of mach/macosx (which has some 
specialized low level functions for dloading) and also for hpux (which uses 
shl_load rather than dlopen) for what will be 1.0.10.  It's still not quite 
correct and is a bit hard to test in part because macosx does not generate 
valid "modules" using automake/autoconf.  It seems the versions that are 
included in Darwin do not know how to use the -bundle flag and other options 
which are needed when creating plugins.

I think resolving issues with the extending dynamic loading to new targets, 
and perhaps fixes for SocketPort/SocketService, should be the focus of 
1.0.10.