Use TypedOutput for Requests.

Refs #141.
Provide a mutable server implementation. Update Server API to conform.
Merge pull request #156 from square/jw/point-to-things

Provide a mutable server implementation. Update Server API to conform.
Log request headers. Update response log format to match.
Merge pull request #157 from square/jw/log-request-more-like-yeah

Log request headers. Update response format to match.
Merge pull request #152 from square/jw/request-typed

Use TypedOutput for Requests.
Fix Url Escaping on GET Parameters

This patch fixes url escaping on url-encoded GET parameters. Query parameters will now be escaped. Test cases for common characters ?, #, and & are included.
Merge pull request #158 from campnic/escape_fix

Fix Url Escaping on GET Parameters
Add UrlConnection Client.

Use this on Android 2.2 and prior and when on the JVM.

Also update our sample to use GitHub contributors rather than the Twitter API because the latter is shutting down and subject to lame rate limiting when on common networks.

Bump some dependencies to their latest versions.
Merge pull request #159 from square/jw/dont-call-it-earl

Add UrlConnection Client.
Merge branch 'master' of git://github.com/square/retrofit