Support line continuation escapes in string literals.
Support line continuation escapes in string literals.

Frky/mujs,ccxvii/mujs,ccxvii/mujs,ccxvii/mujs,earthling42/mujs,evanlabs/mujs,lsm/mujs,BOGY/mujs,ccxvii/mujs,guiquanz/mujs,thurday/mujs