Improve performance of JavaScript lexer.
Improve performance of JavaScript lexer.

Reduce string comparisons and calls to unicode functions in lexText.

unixabg/redwood,andybalholm/redwood,vishnuvaradaraj/redwood,vishnuvaradaraj/redwood,yinheli/redwood-filter,yinheli/redwood-filter,vishnuvaradaraj/redwood,unixabg/redwood,andybalholm/redwood,yinheli/redwood-filter