Fix comment formatting.
Convert plformat segfaults into test failures.

This doesn't fix the logic errors in the parser, it just adds
guards to return early instead of segfaulting. This lets us
continue to the next unit test and get better coverage.
Re-enable the PayloadFormat.MultilineBasicCueText unit test.

This no longer causes a hang under valgrind.
Re-enable CueIdArrow unit tests.

These no longer hang under valgrind.
Expand the multiline-escape test to verify multiline parsing.

Previously the test just checked for the first &nbsp; and
didn't actually verify both lines were parsed.

This fixes the spurious XPASS from the segfault fixes, which
had ciescapecahracter_unittest passing despite multiline
parsing not working.
Add a unit test to verify &nsbp; is parsed after a valid line.
Merge pull request #5 from rillian/plformat2

more fixes