Campaign detection enhancements

[robocoder]

Current design detects campaign_name in the referer as a parameter.

The first enhancement would allow regexp matching since some ad networks use SEF URLs, e.g.,

• !http://abc.yz/ad/123d/piwik.org/campaign_name/redir/http://abc.yz/jump/123

The second enhancement would extend the detection to the landing page URL since some campaigns may not be delivered via an ad network. (Sponsor links and affiliate links come to mind.) This complements #79.

[mattab]

Current design doesn't detect campaign_name in the referer as a parameter, but in the landing page. See #855 for improvement proposals. Maybe we could add detection of parameter in the referer URL but I don't see what use case this would be in (GA doesn't do it)

[robocoder]

What was I drinking/thinking when I wrote that?