Added pointer_stack_error
Added pointer_stack_optimize
Added pointer_stack_buffer
Added missing comment to pointer_stack_buffer
Added pointer_stack_auto_pack
Added pointer_stack_free
Added poiner_stack_invert
Added pointer_stack_unlock
Added pointer_stack_lock

Also changed return type of pointer_stack_unlock. The procedure now reports the status of the lock.
Added pointer_stack_get_count

Documentation updates needed.
Added pointer_stack_get_private
Added pointer_stack_set_private
Added pointer_stack_get_limit
Added pointer_stack_set_limit
Added pointer_stack_pointer
Added pointer_stack_poke
Added pointer_stack_peek