Post SPR-8804 optimizations: better use of HC 4.3 APIs
Merge pull request #350 from ok2c/httpclient_4_3

* httpclient_4_3:
  Post SPR-8804 optimizations: better use of HC 4.3 APIs
Use correct header for version in CONNECTED frame

Previously, the negotiated version was included in the CONNECTED frame
using the accept-version header. This is incorrect. The version
header should be used.
Add StompProtocolHandler tests
Added 'zone' attribute to @Scheduled

Issue: SPR-10456
Added conversion support for Java 8's ZoneId class and the 'of' method convention

Issue: SPR-1528
Polishing
Add option to remove path ext in ServletUriCompBuilder

Issue: SPR-10272
Add basic javadoc to spring-messaging annotations
Add support for Ping and Pong WebSocket messages

Issue: SPR-10876
Release version 4.0.0.M3
Increment version to 4.0.0.BUILD-SNAPSHOT