parseTestRecord: add support for YAML frontmatter
parseTestRecord: initial unit test for test record parser
parseTestRecord: refactor for testing
factor old parsing; add YAML parsing
runner: support "includes" from YAML frontmatter
support frontmatter "includes" in python runner
use test.includes if present instead of scanning test code with regex
harness: factor individual functions out into files
tools: handle YAML errors
tolerate missing keys in dictionary (flags, includes)
report filename when empty frontmatter block
new option --list-includes to test262.py
harness: factor helper functions into separate files
sth: remove extra close-paren (syntax error)
test_common: TDD; failing parse of YAML
common: use parseTestRecord (YAML-aware)
c33bf0e043