Added a CLEANUP mechanism to the exception handling library. Fixed a bug in the way setjmp() return codes were being handled that lead to infinite loops in some cases, exceptions getting missed in others. Made FINALLY {} a required element (unfortunately).

demo/default.c

@@ -5,8 +5,12 @@ int main(void)
 {
   TRY {
     THROW(2, NULL);
+  } CLEANUP {
+  } EXCEPT {
   } DEFAULT {
     EXCLIB_TRACE("Inside of DEFAULT - I catch everything!");
+    return 0;
+  } FINALLY {
   } ETRY;
-  return 0;
+  return 1;
 }