Extra rules when filtering by domain

[igvk]

Initially mentioned in #21.
When getting all filters for domain by GetFiltersForDomain(domain), there are rules that shouldn't be there, because they correspond to some other domains (with domain option).

Here are examples taken from Easylist.

Whitelist rule:
@@||www.google.com/adsense/search/async-ads.js$domain=webcrawler.com
If I call GetWhitelistFiltersForDomain("www.google.com"), I still get this filter in the enumeration, although it definitely is relevant only for the domain webcrawler.com.

Blacklist rule:
||google.com/jsapi?autoload=*%22ads%22$script,domain=youtube.com
and the call to GetFiltersForDomain("www.google.com").