Make CharsetDetector adhere to WHAT-NG recommendation #47
Description
CharsetDetector fails to detect correct character encoding when META tag says charset=UTF-16 but it is in fact in UTF-8. It is because CharsetDetector puts higher priority on META tag over charset detected from content. Reimplement CharsetDetector in reference to WHAT-NG recommendation http://www.whatwg.org/specs/web-apps/current-work/multipage/parsing.html#encoding-sniffing-algorithm
Known internally as ARI-3933.