Implement snaffler rules support

[tigre-bleu]

I know this is quite a big feature, but it would be nice if manspider and snaffler could share the looting rules.

Indeed Snaffler is very good when a Windows machine is available and Manspider could be the alternative with Linux, taking advantage of the quite extensive ruleset.

[TheTechromancer]

That's a great suggestion. I can't make any promises but I'll put it on my to-do list.