Fix multiline cue text error.

The problem was that we were ending on any line that ends with a newline
character. Therefore, we would only parse one line of cue text. I've
set it up so that it ends parsing cue text on a line that is either
empty or consists of only a new line character.
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
Remove read_cuetext adding newline char.

Since we are now reading in the newline char in webvtt_string_getline
we no longer have to add a newline char after the function executes.
Currently it is being added which results in double newlines sometimes.
Remove skip newline logic from read_cuetext.

Since we are reading in the newline character in string_getline we no longer
need to skip the newline character after the fact.
Fix escape tokenizer to end on correct status.

When the escape tokenizer has parsed an escape character sequence properly
or it has found a character that cannot belong to an escape sequency it
should switch it's status to WEBVTT_UNFINISHED so the cue text tokenizer
knows that it is not finished.
Merge pull request #264 from RickEyre/multiline-fix-2

Fix multiline cue text error.