domainrc to manage cross-domain requests (was Re: RequestPolicy-like patch)

p37sitdu wrote:
> Patch implements functions similar to Firefox addon RequestPolicy. [1]
> It allows user to control automatic requests more flexible than
> filter_auto_requests option. Patch removes this option and replaces it
> with file .dillo/domainrc that looks like this:
> 
> default deny
> wikipedia.org .wikimedia.org
> wikisource.org .wikimedia.org
> wikitionary.org .wikimedia.org
> wikiversity.org .wikimedia.org
> 
> That way most requests are denied, but images on wikipedia are loaded
> from wikimedia.org without clicking on them.
> 
> Patterns can start with "." to allow subdomains.
> 
> Special pattern "*" can be used to allow requests to any domains from
> some domain (for example if it is a website full of external images) or
> to allow requests from any domain to some domain (maybe CDN).
> 
> Without domainrc file all cross-domain requests are denied.
> 
> [1] https://www.requestpolicy.com/

Committed with a little dilloification, etc.

At the moment, I have the default set to accept rather than deny,
thinking that it might be easier for us to build up a sample or
default domainrc with a bunch of notorious ad sites to blacklist than
it would be to whitelist enough common sites that use a [site]images.com
or suchlike.