* support more router modes, as long as the firewall and the DNS server
are enabled
* new source sites can be added & changed via awk ruleset in uci config
* source domain count, last update time & overall count will be stored
in uci config
* added 3 new source sites:
   ransomware tracker
   rolist/easylist
   winspy
* switch to minimal inline base64 encoded 1×1 GIF for pixel server
(separate png image no longer needed)
* simplified uci parser
* source download & domain sort optimization
* add whitelist parser with wildcard support
* reduced code size & various cleanups
* updated documentation

Signed-off-by: Dirk Brenken <openwrt@brenken.org>