Use Locale.ROOT instead of Locale.US or Locale.ENGLISH for upper/lower case conversion of locale independent textual identifiers

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpcore/trunk@1584059 13f79535-47bb-0310-9956-ffa450edef68
Initial implementation of the server side request pipelining; unit and integration tests

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpcore/trunk@1584060 13f79535-47bb-0310-9956-ffa450edef68