Include <sys/time.h> in ptimer.c

Without #include <sys/time.h> we don't have access to struct timeval,
which breaks compilation on Unixes without POSIX timers.

2005-06-29  Hrvoje Niksic  <[email protected]>

	* ptimer.c: Include sys/time.h to get struct timeval.

Index: src/ptimer.c
===================================================================
--- src/ptimer.c	(revision 1832)
+++ src/ptimer.c	(working copy)
@@ -59,8 +59,10 @@
 #ifdef HAVE_UNISTD_H
 # include <unistd.h>
 #endif
-#include <assert.h>
 #include <time.h>
+#ifdef HAVE_SYS_TIME_H
+# include <sys/time.h>
+#endif
 
 /* Cygwin currently (as of 2005-04-08, Cygwin 1.5.14) lacks clock_getres,
    but still defines _POSIX_TIMERS!  Because of that we simply use the