adblock-fast: initial commit

adblock-fast: initial commit

* this package replaces simple-adblock package
* it was impossible to keep existing config structure and continue
  improving the simple-adblock the way I wanted, hence the new
  package name
* the migration script for existing simple-adblock config is included in
  the uci-defaults file

Signed-off-by: Stan Grishin <stangri@melmac.ca>