Make sure internal macros end with _

```
Macros don't respect namespaces, so it is sometimes hard for a user to tell
whether a Google Test macro is public or not.

To reduce the likelihood of a user accidentally depend on Google Test's
internal implementation, we should name all internal macros *_ (i.e. ending
with an underscore).

```

Original issue reported on code.google.com by `shiq...@gmail.com` on 2 Jul 2008 at 7:26
