The new design concerns itself with one thing and exactly one thing:
passing values back and forth with an extern "C" function.
This allows to simplify fringe::arch into a single primitive, swap.
Close#21
fix#3
This takes all Valgrind functionality private again.
Valgrind stack registrations are now associated with a Context, not with
a Stack. This makes sense, since it's only actually a stack when a
Context is running on it. Perhaps Valgrind will even be able to detect
early stack frees now.
edef
whitequark
John Ericson