Match contact methods everywhere in the contact string

[jplitza]

In a string like "http://website-of-owner.com by [email protected]", we wouldn't currently recognize the address. Also, the IRC notifier would understand ",isnick" at the end of the URI to signal that the recipient is a user and not a channel, but this will never reach him because it is stripped away.

We could simply leave the string as it is (making #2 obsolete) and match without ^ and $ everywhere. However, to still catch mail addresses without mailto: but also not try to send mails to XMPP addresses, we would have to introduce priorities on the notifier plugins.