Add better help information to quic_client and quic_server.
Also, modify the quic_client to print out the response contents.

Merge internal change: 53403247

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=227365

Review URL: https://codereview.chromium.org/25043005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@227558 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 227558