Patch libevent to compile for 64-bit archs.

external/Makefile

@@ -132,6 +132,9 @@ openssl-clean:
 
 libevent/Makefile:
 	sed -i 's@\(SUBDIRS = . include\) sample test@\1@' libevent/Makefile.am
+	cp libevent-patch-1 libevent
+	-cd libevent && \
+	 	patch -N -p1 --reject-file=- < libevent-patch-1
 	##sed -i 's@\(AC_OUTPUT(Makefile include/Makefile\) test/Makefile sample/Makefile)@\1)@' libevent/configure.in
 	cd libevent && ./autogen.sh
 	cp config.sub libevent

external/libevent-patch-1

@@ -0,0 +1,29 @@
+For some reason arc4random_addrandom isn't present in 64-bit android archs. !
+
+diff --git a/configure.ac b/configure.ac
+index d42edd8..c511be7 100644
+--- a/configure.ac
++++ b/configure.ac
+@@ -290,7 +290,7 @@ AC_HEADER_TIME
+ 
+ dnl Checks for library functions.
+ AC_CHECK_FUNCS([gettimeofday vasprintf fcntl clock_gettime strtok_r strsep])
+-AC_CHECK_FUNCS([getnameinfo strlcpy inet_ntop inet_pton signal sigaction strtoll inet_aton pipe eventfd sendfile mmap splice arc4random arc4random_buf issetugid geteuid getegid getprotobynumber setenv unsetenv putenv sysctl])
++AC_CHECK_FUNCS([getnameinfo strlcpy inet_ntop inet_pton signal sigaction strtoll inet_aton pipe eventfd sendfile mmap splice arc4random arc4random_buf arc4random_addrandom issetugid geteuid getegid getprotobynumber setenv unsetenv putenv sysctl])
+ AC_CHECK_FUNCS([umask])
+ 
+ AC_CACHE_CHECK(
+diff --git a/evutil_rand.c b/evutil_rand.c
+index 284341c..97161e4 100644
+--- a/evutil_rand.c
++++ b/evutil_rand.c
+@@ -174,7 +174,9 @@ evutil_secure_rng_get_bytes(void *buf, size_t n)
+ void
+ evutil_secure_rng_add_bytes(const char *buf, size_t n)
+ {
++#ifdef _EVENT_HAVE_ARC4RANDOM_ADDRANDOM
+ 	arc4random_addrandom((unsigned char*)buf,
+ 	    n>(size_t)INT_MAX ? INT_MAX : (int)n);
++#endif
+ }
+