apinger: Update to latest git revision

This project seems abandoned. Updated to latest version.

Also cleaned up the Makefile quite a bit.

Signed-off-by: Rosen Penev <rosenp@gmail.com>
(cherry picked from dff6d2639e)

net/apinger/patches/010-poll.patch

@@ -0,0 +1,24 @@
+--- a/configure.ac
++++ b/configure.ac
+@@ -23,7 +23,7 @@ AC_HEADER_SYS_WAIT
+ AC_CHECK_HEADERS([arpa/inet.h errno.h malloc.h \
+ 		stddef.h stdlib.h string.h sys/socket.h \
+ 		sys/time.h syslog.h unistd.h time.h \
+-		assert.h sys/poll.h signal.h pwd.h grp.h stdarg.h\
++		assert.h poll.h signal.h pwd.h grp.h stdarg.h\
+ 		limits.h sys/wait.h sched.h sys/ioctl.h sys/uio.h])
+ AC_HEADER_TIME
+ 
+--- a/src/apinger.c
++++ b/src/apinger.c
+@@ -33,8 +33,8 @@
+ #ifdef HAVE_SYS_WAIT_H
+ # include <sys/wait.h>
+ #endif
+-#ifdef HAVE_SYS_POLL_H
+-# include <sys/poll.h>
++#ifdef HAVE_POLL_H
++# include <poll.h>
+ #endif
+ #ifdef HAVE_ARPA_INET_H
+ # include <arpa/inet.h>