Fixes edoc generation in rebar.

Author: Geoff Cant

rebar.config

@@ -27,4 +27,4 @@
  [{"CFLAGS", "$CFLAGS -I/usr/include/libxml2"},
   {"LDFLAGS", "$LDFLAGS -module -avoid-version"}]}.
 
-{edoc_opts, [{def, [{vsn, "0.9.4-HEAD"}]}]}.
+{edoc_opts, [{def, [{vsn, "0.9.4-HEAD"}]}, {packages, false}]}.