Extracted code snippets from Java body parsers documentation
Extracted code snippets from Java content negotiation documentation
Extracted code snippets from Java response documentation
Extracted code snippets from Java routing documentation
Extracted code snippets from Java session flash documentation
Fixed SSE event name regression

The SSE event name should be prefixed with the event: tag, not name:,
according to http://www.w3.org/TR/2009/WD-eventsource-20091029/.

This is a regression just on master, the code is fine on 2.2.x and
earlier.
Merge pull request #2224 from jroper/sse-event-name

Fixed SSE event name regression
Merge pull request #2218 from jroper/java-http-extract-docs

Java HTTP code snippets extraction
Merge remote-tracking branch: upstream/master