Allow to use the original name of the global functions

It is impossible to have two functions with the same name inside the same
program, but it is possible to provide a #define to allow the user code to use
the original function name for the wrapper function, so do it for convenience.

Remove the old changes adding explicit "_wrap_" prefix to the examples and the
tests and remove the few more now passing tests from the list of failing tests.

Examples/test-suite/c/cpp_basic_template_function_runme.c

@@ -2,7 +2,7 @@
 #include "cpp_basic_template_function/cpp_basic_template_function_wrap.h"
 
 int main() {
-    assert(_wrap_GetMaxInt(3, 5) == 5);
+    assert(GetMaxInt(3, 5) == 5);
     
     return 0;
 }