Support for multiple conditions to match a rule

[securitym0nkey]

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redmine issue 2509:

Describe changes:

This adds support to specify multiple conditions to match a rule in {enable,disable}.conf.

Syntax: multi:<match_condition1>;<match_conditios2>;...<match_conditionN>;

Example: Enable all rules including the term "nmap" bust just from the "emerging-scan.rules" file.

multi:filename:rule/emerging-scan.rules; re:nmap;