javascript.pegjs speed

ups made a mistake 
the assignment expression worked only when ended with a ";"

pls do some review ;)

previous pr: https://github.com/dmajda/pegjs/pull/260

issue: https://github.com/dmajda/pegjs/issues/259


text of previous issue again:

this solves my speed issue with javascript.pegjs

most significan change is done to AssignmentExpression
but the other changes all resulted in measurable speed gain by magnitudes.
the AssignmentExpression is the most complex because in breaks a loop to LefthandsdeExpression
but pls review it.

i also think i fixed newExpression.
switched callee:MemberExpression to callee:newExpression
but i am not 100% sure this is how its supposed to be
pls confirm

do you have test cases for this file?