With Android M, the Apache HTTP client is no longer supported.
Removing references to that client and the clients that depend
on it (DefaultHttpClient and AndroidHttpClient). Replacing, when
appropriate, with references to HttpURLConnection.
Also removing references to the 2011 blog post "Android's HTTP
Clients" (https://goto.google.com/cusll) since that post is largely
about the ex-clients.
Fixed a couple of other small errors while I had the files open
(for example, changed a sample URL in a code snippet to the safe
www.example.com).
bug: 19696844
Change-Id: Iabf780140c37d5fc95c0d45542c425a945c69337
Most of them are pointless links to a "text/plain" constant which are
far clearer when inlined with the relevant text.
Change-Id: Iaed51b4548cb2836741106dc19c9cf500c205d32
