* please note: config file update required!
* add 'whitelist only' mode, block access to all domains
  except those explicitly listed in the whitelist file
* rework awk regex for all blocklist sources
  * include 'third-party' domains for all regional lists
  * change adguard url and refine filter ruleset
  * use POSIX character classes
  * fix regex for whitelist preparation
  * fix corner case parsing issues
* fix enable/disable behavior
* various other small fixes
* documentation update

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