Add Screendoor to blocklist

Whitelist screendoor.dobt.co domain.
fix weird null error
Merge pull request #217 from adamjacobbecker/patch-1

Add Screendoor to blocklist
adding facebook to cookie block list because some people want to view facebook comments on third party sites
Merge branch 'master' into feature/allow3rdparties

Conflicts:
	doc/sample_cookieblocklist.txt