[enh] Allow to disable network discovery

[es-core] Synchro now listen peers changes, throw WebSocket

- better log prefix on websocket server

- Synchro: use scroll request
- Make sure maven using version >= 3.1

Upgrade to java 1.8
[core] Add config option to reload as part of the BC
[core] Fix unit test config file
[core] Peer: mark peers as DOWN is not alive since X time

Upgrade to java 1.8
[core] Add config option to reload as part of the BC
[core] Fix unit test config file
[core] Peer: mark peers as DOWN is not alive since X time

 - Add new index /page (renamed for old /registry)

[enh] better index user WOT leave events
[enh] add certCount in <currency>/blockstat index

[fix] peer index not executed
[fix] email subcription not executing
[enh] Better message when error on http request
[enh] new option to send email subscription at startup

- Peer: Add BMATOR endpoint API