Updated to Netty 4.0.5.Final-SNAPSHOT
Updated .travis to use new ci tag for Netty and Netty subsystem.
Adding a WebSocket heartbeat interval of 30 mins.
Removing the second building of subsytem-api and subsystem.
Building Netty all as subsystem depends on all and not only codec-sockjs
Merge branch 'danbev-AGPUSH-180-update-netty'