Add wxOVERRIDE to test files

And cleanup some tailing spaces and tabs.

tests/controls/datepickerctrltest.cpp

@@ -30,8 +30,8 @@ class DatePickerCtrlTestCase : public CppUnit::TestCase
 public:
     DatePickerCtrlTestCase() { }
 
-    void setUp();
-    void tearDown();
+    void setUp() wxOVERRIDE;
+    void tearDown() wxOVERRIDE;
 
 private:
     CPPUNIT_TEST_SUITE( DatePickerCtrlTestCase );