Added readable matcher support, using Readability type class.
Added writable matcher support, using Writability type class.
Merging in Chee Seng's readability and writability enhancements with conflicts fixed.

Conflicts:
	project/GenFactories.scala
	src/main/resources/org/scalatest/ScalaTestBundle.properties
	src/main/scala/org/scalatest/matchers/Matcher.scala
	src/main/scala/org/scalatest/words/MatcherWords.scala