Merge pull request #5 from fatalbanana/master

Small fix for rbl.lua - properly check for empty source IP
Fix surbl module.
Add uribl.com to configuration.
Log debug messages from libraries.
Fix dkim canonization for folded headers.
Fix formatting and variables usage.
Reduce false positive rate in urls detection.
Refuse empty emails in urls detection as well.
Avoid endless recursion while pushing ucl arrays to lua.
Do not try to register rbls without a symbol.
Fix fuzzy check configuration.
Add missing symbols.
Add 0.6.0 ChangeLog entry.
Fix debian spec.
Added tag 0.6.0 for changeset e11d0fa6d580
Some fixes for Debian package
Change bayes db size