Stronger safe_email filter

[fredrikekelund]

I really like the inclusion of the safe_email Twig filter! I realize that it's no bullet proof method for protecting from email harvesters, but strengthening it somewhat would still feel good.

Maybe taking a cue from WordPress is a good idea here, the antispambot function encodes random parts of the address as HTML entities (both decimal encoding and hex encoding) and other parts as their default character representation.

[rhukster]

done!