deflate-encoded response bodies.  [Feature #6942]
* lib/net/http/generic_request.rb:  Automatically accept gzip and
  deflate content-encoding for requests.  [Feature #6494]
* lib/net/http/request.rb:  Updated documentation for #6494.
* lib/net/http.rb:  Updated documentation for #6492 and #6494, removed
  Content-Encoding handling now present in Net::HTTPResponse.
* test/net/http/test_httpresponse.rb:  Tests for #6492
* test/net/http/test_http_request.rb:  Tests for #6494
* test/open-uri/test_open-uri.rb (test_content_encoding):  Updated test
  for automatic content-encoding handling.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@36473 b2dd03c8-39d4-4d8f-98ff-823fe69b080e