Highlight: experimental transactional support

Change list
-----------------
 - #1006, revert the display clock to original version
 - #1004, fix transactional state compile failure
 - #6, add transaction api
 - #902, delete kafka topic on close
 - #826: upgraded to visjs 4.1.0-develop
 - #924, show application name and status on "gear info"
 - #981, add prompt for ClassNotFoundException