ACTIVEMQ6-49 removing chinese quickstart doc

https://issues.apache.org/jira/browse/ACTIVEMQ6-49

Some left over from the chinese docs
ACTIVEMQ6-20 removing twitter integration

https://issues.apache.org/jira/browse/ACTIVEMQ6-20

this has been identified as a dead feature.
It was only useful for presentations...
it had its time and we have better examples we can use...
It's time for this feature to go!