Zevenet Community Edition v5.9

This release includes the following changes:

New features:
[networking] IPv6 support
[system] 64 bits support
[farms] new L4xNAT core based on nftables and nftlb
[farms] supported additional L4xNAT load balancing protocols: SIP,
FTP, TFTP, SCTP, AMANDA, H323, IRC, NETBIOS-NS, PPTP, SANE and SNMP.
[farms] add L4xNAT direct server return support
[gui] new WebGUI with Angular6 based in ngx-admin template
[api] new Zevenet API 4.0
[guardian] an easier configuration system for farm guardian.

Improvements:
[system] fix security issues Spectre and Meltdown
[system] kernel update (Debian Buster)
[system] improved support for hypervisors
[system] improved code refactoring