Use TypedOutput for Requests.

Refs #141.
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.
Fix inconsistencies in javadocs.

These changes were made with consistency in mind, in relation to the rest of the project:
 - Change self-closing <p/> tags to regular <p> tags.
 - Add missing <p> tags.
Merge pull request #160 from dlam/master

Fix inconsistencies in javadocs.
Remove usage of HTTP constants class from Apache dependency.
Relax enforcement of UTF-8 and use the body charset for decoding.

Consumers wanting well-behaved endponts should override or add to their `toBody` charset enforcement:

```java
String charset = Utils.parseCharset(body.mimeType());
if (!"UTF-8".equalsIgnoreCase(charset)) {
  throw new ConversionException("Invalid charset " + charset + ". Must be UTF-8");
}
```

Closes #163.
Merge pull request #164 from square/jw/charset

Relax enforcement of UTF-8 and use the body charset for decoding.
Make Utils constructor private.
Add response object to callback success.

Gives access to response headers while still converting response within retrofit.
Fix wrapper scope and callback param ordering.
Make response wrapper members final.
Merge pull request #165 from jjNford/master

Always return response object on success callbacks.
Full type resolution from Gson.

There's a ton of code because we need to construct generic types.
Merge pull request #167 from square/jwilson/types

Full type resolution from Gson.
Style tweaks.