Change behavior of jb_check and jb_assert if DEBUG is defined before including util.h:  Clear errno, and, if check fails, abort.
Change behavior of jb_check and jb_assert if DEBUG is defined before
including util.h:  Clear errno, and, if check fails, abort.

jefbed/libjb,jefbed/xstatus,jefbed/xstatus,jefbed/xstatus,jefbed/xstatus,jefbed/libjb