Make "ext" participate in may_include.

Also, resolve a circular dependency involving the use of lib/log by
csiphash.c.

src/ext/.may_include

@@ -0,0 +1,10 @@
+
+orconfig.h
+
+lib/err/*.h
+lib/cc/*.h
+
+tinytest*.h
+ext/siphash.h
+ext/byteorder.h
+ext/tor_readpassphrase.h

src/ext/csiphash.c

@@ -30,12 +30,12 @@
 */
 
 #include "lib/cc/torint.h"
-#include "lib/log/util_bug.h"
+#include "lib/err/torerr.h"
 
-#include "siphash.h"
+#include "ext/siphash.h"
 #include <string.h>
 #include <stdlib.h>
-#include "byteorder.h"
+#include "ext/byteorder.h"
 
 #define ROTATE(x, b) (uint64_t)( ((x) << (b)) | ( (x) >> (64 - (b))) )
 
@@ -112,13 +112,13 @@ static int the_siphash_key_is_set = 0;
 static struct sipkey the_siphash_key;
 
 uint64_t siphash24g(const void *src, unsigned long src_sz) {
-	tor_assert(the_siphash_key_is_set);
+	raw_assert(the_siphash_key_is_set);
 	return siphash24(src, src_sz, &the_siphash_key);
 }
 
 void siphash_set_global_key(const struct sipkey *key)
 {
-	tor_assert(! the_siphash_key_is_set);
+	raw_assert(! the_siphash_key_is_set);
 	the_siphash_key.k0 = key->k0;
 	the_siphash_key.k1 = key->k1;
 	the_siphash_key_is_set = 1;

src/ext/readpassphrase.c

@@ -30,7 +30,7 @@
 #include <signal.h>
 #include <ctype.h>
 #include <fcntl.h>
-#include "tor_readpassphrase.h"
+#include "ext/tor_readpassphrase.h"
 #include <errno.h>
 #include <string.h>
 #include <unistd.h>