Fix a bug where we weren't storing rewritten request headers.

Closes https://github.com/square/okhttp/issues/947
Merge pull request #948 from square/jwilson_0619_vary_accept_encoding

Fix a bug where we weren't storing rewritten request headers.
Upgrade to Bouncy Castle 1.50

Release notes:

https://www.bouncycastle.org/releasenotes.html
Merge pull request #952 from andrewgaul/bouncy-castle-1.50

Upgrade to Bouncy Castle 1.50
2.0 release notes.
[maven-release-plugin] prepare release parent-2.0.0
[maven-release-plugin] prepare for next development iteration
Unindent the website samples.
Merge pull request #953 from square/jw/unindent

Unindent the website samples.
Merge branch 'okhttp_20'

* okhttp_20:
  [maven-release-plugin] prepare for next development iteration
  [maven-release-plugin] prepare release parent-2.0.0
Fix a bug where the cacheResponse's request method was wrong.

We were returning the message (like 'OK') rather than the method
(like 'GET'). Ugh.
Merge pull request #955 from square/jwilson_0621_fix_cache_method_typo

Fix a bug where the cacheResponse's request method was wrong.
Implement HTTP/2 Draft 13; HPACK Draft 08.
Merge pull request #954 from square/adrian.http2draft13

Implement HTTP/2 Draft 13; HPACK Draft 08.
fixed merge conflicts after pulling from upstream