Bump to 3.4.4

- fix sys config merging
- Fix relative src_dir specifications to avoid
  double .app.src file detection
- Recompile when include files change in
  non-default directories

src/rebar.app.src

@@ -3,7 +3,7 @@
 
 {application, rebar,
  [{description, "Rebar: Erlang Build Tool"},
-  {vsn, "git"},
+  {vsn, "3.4.4"},
   {modules, []},
   {registered, []},
   {applications, [kernel,