Javadocs.

git-svn-id: http://kryo.googlecode.com/svn/trunk@400 a9660ef0-a895-11de-8ba5-91705c1537ed
Use factory pattern for instantiation of serializers (merged patch provided by issue 121).

git-svn-id: http://kryo.googlecode.com/svn/trunk@401 a9660ef0-a895-11de-8ba5-91705c1537ed