- Improve callback to give context sensitive information about the

- Improve callback to give context sensitive information about the
  different statuses and print the thread ID that it was called from.
- Replace the busy waiting on the "goon" flag with an event.
- Replace hard coded numbers with more informative constants
  throughout the InternetReadFile test.
- Add tests for InternetReadFileExA.
- Fix the error value from calling InternetReadFile with a NULL handle
  as indicated by the test.