boostrapize UI
send WS messages in Json format
make UI more attractive

* replace bootstrap with pure
* limit evetns to 15
* display events most recent first
* display events in table
added protocol listener logic to Raft context

listeners can now be notified of incoming events. Note this might introduce the possibility of refactoring the code
to ensure all operations goes through listening logic, decoupling execution from interface a little bit more.
wire protocol listeners into modules and context

websocket emitter implements RaftProtocolListener but is currently no-op
ws listener actually send protocol events to clients
remove dummy messages
test and fix UI for demo

remove dot in messages types names to be able to use them as class names in interface
fix error in disconnect
format messages according to structure