All Microsoft-contributed *.js and *.py sources now have Ecma's copyright header.

FindTestCaseIssues.py is a new helper script which can be used to detect issues with the format of test cases (e.g., runTestCase not being called).

FixPathsAndIds.py now preserves line endings and the BOM.

host objects (which make them invalid for test262).  Using this, I found one benign 'alert'
usage (it was never even called) and removed it.