On error while streaming, display both chunks
All tests pass streaming chunks
- Need first line before parsing header.
- Handles CR-LF endings properly, passes all tests.
- Removed advance arg from collectNextLine.
- Simple test if header has bad double webvtt.
- Enter BADWEBVTT state on invalid header thus ignore further parsing.
Merge pull request #126 from jespirit/header-fix

Closes #125.