Changes to error_xsb.[ch] to turn current xsb_throw to xsb_throw_internal, and then re-introduce xsb_throw(). This allows xsb_throw to be used more easily by foreign C functions and will hopefully solve Roberto Bagnara's problem.
Other changes fixed some typos in error messages.
Authored by: tswift 2006-10-08
Parent: [r4984]
Child: [r4986]