Clarify bootstrap-vs-autoreconf usage

* README-hacking: Tell people to run ./bootstrap.
diff --git a/README-hacking b/README-hacking
index d2dfdd3..16d12c0 100644
--- a/README-hacking
+++ b/README-hacking
@@ -2,8 +2,9 @@
 ============
 If you use the GIT version of strace there will be some files missing
 that you need to build strace.  These files are generated by tools from
-the GNU Autoconf and Automake packages.  You need recent versions, which
-provide the `autoreconf -i' command that will do everything you need.
+the GNU Autoconf and Automake packages.
+
+Note: rather than run `autoreconf' directly, use the `./bootstrap' script.
 
 
 No more ChangeLog file