Portability testers, please: getting the stack base

[Marius Vollmer]

Hi,

I have finally added code to libguile to find the stack base.  This
means that it is no longer necessary to use scm_boot_guile, you can
also use the newer scm_init_guile, which will return immediatly after
initializing Guile.

However, the code is *very* platform dependent and I can't really test
it.  So please update from CVS and try to compile when you think you
have an unusal platform.