Added a lang parameter to getStopWords().
Added the lang parameter to the interface. All we need now is to connect
it down to StopWords.

Also, removed the superfluous one-parameter extractContent method.
Fully wired lang in.
Language is transfered for each url and not in Goose configuration

Merge remote-tracking branch 'remotes/david/language_awareness'

Conflicts:
	src/main/scala/com/gravity/goose/Crawler.scala
	src/main/scala/com/gravity/goose/Goose.scala
	src/main/scala/com/gravity/goose/extractors/ContentExtractor.scala
	src/main/scala/com/gravity/goose/outputformatters/OutputFormatter.scala
	src/main/scala/com/gravity/goose/text/StopWords.scala