Httplib2

This is the first release by new httplib2 team. See post by Joe
https://bitworking.org/news/2016/03/an_update_on_httplib2

Remove VeriSign Class 3 CA from trusted certs
https://googleonlinesecurity.blogspot.com/2015/12/proactive-measures-in-digital.html

Add IdenTrust DST Root CA X3
https://github.com/httplib2/httplib2/pull/26

Support for specifying the SSL protocol version (Python v2)
https://github.com/jcgregorio/httplib2/issues/329

On App Engine use urlfetch's default deadline if None is passed.

Fix TypeError on AppEngine “__init__() got an unexpected keyword argument 'ssl_version’”
https://github.com/httplib2/httplib2/pull/12

Send SNI data for SSL connections on Python 2.7.9+
Verify the server hostname if certificate validation is enabled
https://github.com/httplib2/httplib2/pull/13

Add proxy_headers argument to ProxyInfo constructor
https://github.com/httplib2/httplib2/pull/21

Make disable_ssl_certificate_validation work with Python 3.5.
https://github.com/httplib2/httplib2/pull/15

Fix socket error handling
https://github.com/httplib2/httplib2/commit/eb7468561714a5b700d5a3d8fa1a8794de02b9ef
https://github.com/httplib2/httplib2/commit/e7f6e622047107e701ee70e7ec586717d97b0cbb

Fixes in this release:

https://github.com/jcgregorio/httplib2/pull/313

Fix incorrect ResponseNotReady exceptions, retry on transient errors.

Fixes in this release:

https://github.com/jcgregorio/httplib2/pull/296

There was a problem with headers when a binary string is passed (like
b'Authorization').

https://github.com/jcgregorio/httplib2/pull/276

Default to doing DNS resolution through a proxy server if present.

Heartbleed

More fixes for the App Engine support.

Added a new feature that allows you to supply your own provider for the
CA_CERTS file. Just create a module named ca_certs_locater that has a method
get() that returns the file location of the CA_CERTS file.

Lots of clean up of the code formatting to make it more consistent.

More fixes for App Engine, now less likely to swallow important exceptions.
Adding proxy_info_from_* methods to Python3. Reviewed in https://codereview.appspot.com/6588078/.
Added GeoTrust cert
Make httplib2.Http() instances pickleable. Reviewed in https://codereview.appspot.com/6506074/

The following issues have been fixed:

229 python3 httplib2 clobbers multiple headers of same key
230 Expose meaningful exception for App Engine URLFetch ResponseTooLargeError
231 Expose App Engine URLFetch DeadlineExceededError for debugging purposes