Temporarily revert to using Gson instance directly.

Until Gson 2.4 is released, this is the only way to ensure that the configuration of the Gson instance (e.g., not serializing nulls) is honored when writing values.

Moshi 1.0.0.

Improve error handling in RxJavaCallAdapterFactory

Consolidate response body specializations as inner classes.

Consolidate built-in converters as inner classes.

Use a correct implementation of path encoding.

HEAD requests must use Void response type.

Use execute() instead of enqueue() in Rx adapter

Retrofit should leave threading up to the Scheduler used to invoke call().

Otherwise, there can be two types of unwanted behavior:

1. It can execute on another Thread when sync behavior is desired.

2. It uses unnecessary extra Threads even when already called on a Scheduler.

Shutdown MockWebServer so process exits cleanly.

Provide Retrofit to response callback. Add error converter sample.

Expose request and response converter query methods.

Add delegation support to CallAdapter.Factory.

Use form-data subtype for multipart requests.

Added extra caution before calling onError/onCompleted

The chances are low (but not zero) of an unsubscription between onNext() and
the terminal event.

Remove outdated reference to `Retrofit.Builder#addConverter(Type, Converter)`

Provide option for eagerly validating an interface.

Updating dependencies version

Switch to a generic to/from converter, explicit factory.

This allows for specialization based on for what purpose the converter is being created. For the built-in converter factory, for example, types like `ResponseBody` and `Void` only apply to the response type and types like `RequestBody` only apply to a body/part type.

Add built-in support for Void type which just closes body.