Web interface: refactor for profile support. Refs #2958
Stub implementation for lists download. Refs #2959

Modification:
* new template for /etc/squid/blacklists
* new properties CustomListURL and Lists
* new web interface
* new nethserver-squidguard-downloadlists event
Web UI: multiple-profile stub implemention. Refs #2958
Web UI: download blacklists in background. Refs #2959
Web UI: add roles. Refs #2958
Web UI: time table stub implementation. Refs #1984
Web UI: rename classes. Refs #2958
Web UI: move BlockIpAccess inside filters. Refs #2958