Bug 543151, part A1: Preliminary cleanups to the scanner/parser interface and the organization of nsCSSScanner.cpp. r=heycam
Bug 543151, part A2: Introduce the new peek/advance API and reimplement the old read/pushback API on top of it. r=heycam
Bug 543151, part A3: convert the scanner to use peek/advance. r=heycam
Bug 543151, part A4: unify the inner text-scanning loops used by GatherIdent, ScanString, NextURL. r=heycam