Update to psr/http-message 0.3.0

This patch adds compatibility in phly/http for psr/http-message 0.3.0. In doing so, it introduces some backwards incompatible breaks, including:

- `Phly\Http\Request` no longer accepts an HTTP protocol version as a constructor argument. Use `setProtocolVersion()` instead.
- `Phly\Http\Request` now uses `php://memory` as the default body stream. (`IncomingRequest` uses `php://input` as the default stream.)
- `Phly\Http\RequestFactory` has been renamed to `Phly\Http\IncomingRequestFactory`
  - It also now expects an `IncomingRequestInterface` if passed a request object to populate.
- `Phly\Http\Server::createServer()` now expects 4 additional arguments:
  - `$query`, usually `$_GET`
  - `$body`, usually `$_POST`
  - `$cookies`, usually `$_COOKIE`
  - `$files`, usually `$_FILES`
- `Phly\Http\Server` now composes a `Psr\Http\Message\IncomingRequestInterface` instance, not a `Psr\Http\Message\RequestInterface` instance. This has the implication that all handlers will now receive more specifically an `IncomingRequest`. The change affects each of the following method signatures:
  - `__construct()`
  - `createServer()`
  - `createServerFromRequest()`
  

- `Phly\Http\MessageTrait::setProtocolVersion($version)`, per changes in PSR-7 (this is now defined in the `MessageInterface`).
- Note in `Phly\Http\Stream::read()`'s `@return` annotation indicating that it can also return boolean `false`.
- `Phly\Http\IncomingRequest`, which implements `Psr\Http\Message\IncomingRequestInterface` and provides a server-side request implementation with accessors for each type of request datum typically accessed (cookies, matched path parameters, query string arguments, body parameters, and upload file information). It uses `php://input` as the default body stream.
- `Phly\Http\IncomingRequestFactory` (which replaces `Phly\Http\RequestFactory`)
  - `fromGlobals($server, $query, $body, $cookies, $files)` factory method for creating an `IncomingRequest` instance from superglobals; all arguments are optional, and, if not provided, will be derived from the relevant superglobal.
- `Phly\Http\Server::createServer()` now expects 4 additional arguments:
  - `$query`, usually `$_GET`
  - `$body`, usually `$_POST`
  - `$cookies`, usually `$_COOKIE`
  - `$files`, usually `$_FILES`


- `Phly\Http\Request` no longer accepts an HTTP protocol version as a constructor argument. Use `setProtocolVersion()` instead.
- `Phly\Http\Server` no longer works with standard `Psr\Http\Message\RequestInterface` implementations; it requires `Psr\Http\Message\IncomingRequestInterface` implementations.


- `Phly\Http\RequestFactory` (it is now `Phly\Http\IncomingRequestFactory`)


- `Phly\Http\Stream::read()` now returns boolean false when the stream is not readable, or no resource is present.