Add support to explicitly set the enabled SSL protocols

For some reason when the server uses SSLv3 the lib is not able to decode
the messages properly. To workaround this issue it's needed to set the
enabled protocols to SSLv3 (only).

This patch enables to explicitly set the enabled protocols.

For more info: https://github.com/koush/AndroidAsync/issues/174
Merge pull request #176 from luisgabriel/master

Add support to explicitly set the enabled SSL protocols
Introduce method to adjust SSLEngine parameters via AsyncSSLSocketMiddleware
Merge in upstream/master, and redo configurator API to support multiple AsyncSSLEngineConfigurators.
Restore legacy constructor.
Merge pull request #180 from gdaniels/master

Add API for configuring SSLEngines to AsyncSSLSocketMiddleware
InflaterInputFilter strict mode fix: call inflater.end
Rearrange where the default SSLContext lives.
SSL: Add some experimental code for negotiation (commented out)
Future refactoring and add ConvertFuture.
Multipart now uses long lengths. Allows setting of content-type.
Fix bug in conditional cache response if content-length exists.
More careful location error handling.
Caching: Remove transfer encoding and content encoding headers.
Set Content-Lenght.
Add new growing smart allocator to consolidate code.
Refactor 304 responses and cached responses in http response cache.
Workarounds the L preview.
Merge branch 'master' of https://github.com/koush/AndroidAsync

# By Koushik Dutta (9) and others
# Via Koushik Dutta (3) and Glen Daniels (1)
* 'master' of https://github.com/koush/AndroidAsync:
  Workarounds the L preview.
  Add new growing smart allocator to consolidate code. Refactor 304 responses and cached responses in http response cache.
  Caching: Remove transfer encoding and content encoding headers. Set Content-Lenght.
  Fix bug in conditional cache response if content-length exists. More careful location error handling.
  Multipart now uses long lengths. Allows setting of content-type.
  Future refactoring and add ConvertFuture.
  SSL: Add some experimental code for negotiation (commented out)
  Rearrange where the default SSLContext lives.
  InflaterInputFilter strict mode fix: call inflater.end
  Restore legacy constructor.
  Introduce method to adjust SSLEngine parameters via AsyncSSLSocketMiddleware
  Add support to explicitly set the enabled SSL protocols