for modules.

* eval.c (rb_set_safe_level): should set safe level in curr_thread
  as well.

* eval.c (safe_setter): ditto.

* object.c (rb_obj_is_instance_of): nil belongs to false, not true.

* time.c (make_time_t): proper (I hope) daylight saving time
  handling for both US and Europe.  I HATE SUMMER TIME!

* eval.c (rb_thread_wait_for): non blocked signal interrupt should
  stop the interval.

* class.c (rb_mod_clone): should copy method bodies too.

* bignum.c (bigdivrem): should trim trailing zero bdigits of
  remainder, even if dd == 0.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_6@1307 b2dd03c8-39d4-4d8f-98ff-823fe69b080e