Add PERMIT BOTH option, and minor enhancements

1) Add PERMIT ALL as a list type (allows whitelisting without alias->multiple manual rules)
2) Fix typo "beggining"
3) Improve SWITCH-CASE code flows in 2 places (avoid dup. code)
4) Improve explanatory text for deny/permit

Files modified:
  "pfblocker.inc"
  "pfblocker_lists.xml"