Switch tmux to use autoconf and automake.

Although they suck, they suck less than the alternatives.

autogen.sh

@@ -0,0 +1,15 @@
+#!/bin/sh
+
+[ -z "$AUTOMAKE_VERSION" ] && export AUTOMAKE_VERSION=1.10
+[ -z "$AUTOCONF_VERSION" ] && export AUTOCONF_VERSION=2.65
+
+die()
+{
+    echo "$@" >&2
+    exit 1
+}
+
+mkdir -p etc
+aclocal || die "aclocal failed"
+automake --add-missing --force-missing --copy --foreign || die "automake failed"
+autoreconf || die "autoreconf failed"