fgets test gets skipped

The test for how fgets handles non-blocking pipes is skipped because it apparently fails.

Included are two patches for consideration;

• 0001 fixes the test by checking its behavior as discussed in #1903 (moved), #2045 (moved), and described by the C99 and C11 standards.
• 0002 uses the test_* macros which the majority of the other tests use. I'm not sure if the tt_* or the test_* functions are preferred.