Add IsAutomaticTest() function to the unit tests.

This allows to easily test if we're running on a buildbot slave and disable
some difficult to debug test failures there.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@71634 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

tests/testprec.h

@@ -126,6 +126,8 @@ extern void SetProcessEventFunc(ProcessEventFunc func);
 
 extern bool IsNetworkAvailable();
 
+extern bool IsAutomaticTest();
+
 // Helper class setting the locale to the given one for its lifetime.
 class LocaleSetter
 {