sth: correct syntax error in new fn isAsyncTest
Merge pull request #52 from smikes/syntax-error-isAsyncTest-sth

sth: correct syntax error in new fn isAsyncTest
CONTRIBUTING: add notes on async

add a table showing which print handle to use when
running async tests through test262.py runner

@anba contributed information about async tests in
SpiderMonkey and JavaScriptCore
Merge pull request #53 from smikes/CONTRIBUTING-async-printhandles

CONTRIBUTING: add notes on async
Fix suspect formatting in S15.2.3.1_A3
Normalize testcase format

This commit normalizes the test case format used across test262. It applies the following transformations:

* Convert to YAML for frontmatter
* Remove of trailing whitespace
* Replace /r/n with /n except in chapters 6 and 7.
* Copyright header always uses // comments
* new includes attribute replaces $INCLUDE
* No implicit assumptions about test environment other than $ERROR. Everything else appears in the include array. This includes "runTestCase" which is now included in a substantial number of tests.
Add path attribute.