attribute check timer (trunk only)

Move the counter for the next attribute check to the context
structure.

This increments patchlevel so previous save and bones
files are unuseable after applying.

include/extern.h

@@ -95,7 +95,6 @@ E void NDECL(set_moreluck);
 E void NDECL(restore_attrib);
 E void FDECL(exercise, (int,BOOLEAN_P));
 E void NDECL(exerchk);
-E void NDECL(reset_attribute_clock);
 E void FDECL(init_attr, (int));
 E void NDECL(redist_attr);
 E void FDECL(adjabil, (int,int));