Context methods are non-static - accessed via interface

This is a move towards allowing multiple contexts - with the concept of a (possibly thread local) "current" context

include/internal/catch_test_case_registry_impl.hpp

@@ -109,7 +109,7 @@ namespace Catch {
                                     const char* name, 
                                     const char* description,
                                     const SourceLineInfo& lineInfo ) {
-        Context::getTestCaseRegistry().registerTest( TestCaseInfo( testCase, name, description, lineInfo ) );
+        getCurrentContext().getTestCaseRegistry().registerTest( TestCaseInfo( testCase, name, description, lineInfo ) );
     }
     
 } // end namespace Catch