Moved deprecated classes; fixed some deprecation warnings

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpcore/trunk@1558075 13f79535-47bb-0310-9956-ffa450edef68
Added missing @Override annotations (Java 1.6)

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpcore/trunk@1558077 13f79535-47bb-0310-9956-ffa450edef68
Use String methods and constructors that require Charset instead of String

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpcore/trunk@1558078 13f79535-47bb-0310-9956-ffa450edef68