Disable test mode by default - breaks many tests

theano/configdefaults.py

@@ -203,6 +203,6 @@ AddConfigVar('warn.sum_div_dimshuffle_bug',
 
 AddConfigVar('compute_test_value',
         "If True, Theano will run each op at graph build time, using Constants, SharedVariables and the tag 'test_value' as inputs to the function. This helps the user track down problems in the graph before it gets optimized.",
-        EnumStr(True, False, 'warn', 'err'))
+        EnumStr(False, True, 'warn', 'err'))