harness: remove unused code

Remove some functions that are no longer used. 
Stop `test262.py` including files that provide never-used functions

sta.js:
slight change to Test262Error() semantics; message property now always set
(default "")
remove 2009 copyright in favor of 2012 copyright
remove never-used fn testFailed
remove obsolete fn $INCLUDE

ed.js: remove commented-out obsolete code

cth.js: file is never used

test262.py: don't include ed, cth in console tests
remove two always-included harness files that provide no functions used by any extant test