Important BSD version of setenv, added killpg, replaced _sigsetjmp.c with

an assembler jump to longjmp.

lib/posix/_killpg.c

@@ -0,0 +1,13 @@
+#include <lib.h>
+#define killpg	_killpg
+#define kill	_kill
+#include <signal.h>
+
+PUBLIC int killpg(pgrp, sig)
+int pgrp;			/* which process group is to be sent the
+				 * signal
+				 */
+int sig;			/* signal number */
+{
+  return kill(-pgrp, sig);
+}