Move BUILD_TIME and VCS_INFO macros

I have moved these macros from rebar_core.erl to rebar.erl
in order to prevent eunit tests from failing (which they
currently are).

src/rebar.erl

@@ -33,6 +33,14 @@
 
 -include("rebar.hrl").
 
+-ifndef(BUILD_TIME).
+-define(BUILD_TIME, "undefined").
+-endif.
+
+-ifndef(VCS_INFO).
+-define(VCS_INFO, "undefined").
+-endif.
+
 %% ====================================================================
 %% Public API
 %% ====================================================================

src/rebar_core.erl

@@ -34,14 +34,6 @@
 -include("rebar.hrl").
 
 
--ifndef(BUILD_TIME).
--define(BUILD_TIME, "undefined").
--endif.
-
--ifndef(VCS_INFO).
--define(VCS_INFO, "undefined").
--endif.
-
 %% ===================================================================
 %% Public API
 %% ===================================================================