HTTP Client Upgrade Handler Compare Issue

Motivation:
The HttpClientUpgradeHandler attempts to compare a supported codec against the input codec but the comparison logic is reversed.

Modification:
Negate the logic in HttpClientUpgradeHandler so an error is detected in the error condition.

Result:
HttpClientUpgradeHandler should not fail the upgrade when the input protocol is valid.
HTTP/2 Draft 15

Motivation:
A new draft of the HTTP/2 spec has been released.

Modifications:
Make updates as defined in https://tools.ietf.org/html/draft-ietf-httpbis-http2-15

Result:
HTTP/2 codec is draft 15 compliant.
HTTP/2 throw statement missed

Motivation:
The DefaultHttp2FrameWriter has an exception generated but is missing the throw keyword.

Modifications:
Insert the missing throw keyword.

Result:
Exception thrown when it was intended to be thrown.