Use signal.h, not sys/signal.h.

This is patch 2673214 from mmadia.  It is correct, since we unconditionally
include signal.h in many other places, and only sometimes include sys/signal.h.
It is necessary to compile on Haiku, I'm told.

svn:r1228

ChangeLog

@@ -5,6 +5,7 @@ Changes in 2.0.2-alpha:
  o Add a flag to disable checking environment varibles when making an event_base
  o Disallow setting less than 1 priority.
  o Fix a bug when removing a timeout from the heap. [Patch from Marko Kreen]
+ o Use signal.h, not sys/signal.h. [Patch from mmadia]
 
 Changes in 2.0.1-alpha:
  o free minheap on event_base_free(); from Christopher Layne

configure.in

@@ -63,7 +63,7 @@ AM_CONDITIONAL(ZLIB_REGRESS, [test "$have_zlib" != "no"])
 
 dnl Checks for header files.
 AC_HEADER_STDC
-AC_CHECK_HEADERS(fcntl.h stdarg.h inttypes.h stdint.h stddef.h poll.h signal.h unistd.h sys/epoll.h sys/time.h sys/queue.h sys/event.h sys/param.h sys/ioctl.h sys/select.h sys/devpoll.h port.h netinet/in.h netinet/in6.h sys/socket.h sys/uio.h arpa/inet.h sys/eventfd.h sys/mman.h sys/sendfile.h)
+AC_CHECK_HEADERS(fcntl.h stdarg.h inttypes.h stdint.h stddef.h poll.h unistd.h sys/epoll.h sys/time.h sys/queue.h sys/event.h sys/param.h sys/ioctl.h sys/select.h sys/devpoll.h port.h netinet/in.h netinet/in6.h sys/socket.h sys/uio.h arpa/inet.h sys/eventfd.h sys/mman.h sys/sendfile.h)
 if test "x$ac_cv_header_sys_queue_h" = "xyes"; then
 	AC_MSG_CHECKING(for TAILQ_FOREACH in sys/queue.h)
 	AC_EGREP_CPP(yes,

test/bench_cascade.c

@@ -36,9 +36,9 @@
 #include <windows.h>
 #else
 #include <sys/socket.h>
-#include <sys/signal.h>
 #include <sys/resource.h>
 #endif
+#include <signal.h>
 #include <fcntl.h>
 #include <stdlib.h>
 #include <stdio.h>

test/bench_http.c

@@ -36,7 +36,6 @@
 #include <windows.h>
 #else
 #include <sys/socket.h>
-#include <sys/signal.h>
 #include <sys/resource.h>
 #endif
 #include <fcntl.h>

test/regress_util.c

@@ -34,7 +34,6 @@
 #endif
 #ifndef WIN32
 #include <sys/socket.h>
-#include <sys/signal.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>
 #include <unistd.h>
@@ -42,6 +41,7 @@
 #ifdef _EVENT_HAVE_NETINET_IN6_H
 #include <netinet/in6.h>
 #endif
+#include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>

test/regress_zlib.c

@@ -37,10 +37,10 @@
 #ifndef WIN32
 #include <sys/socket.h>
 #include <sys/wait.h>
-#include <sys/signal.h>
 #include <unistd.h>
 #include <netdb.h>
 #endif
+#include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>