Fixed GUI Patch level parsing

GUI patch level item could be a string in older versions, or a single byte integer in newer ones (thanks Victor!)
Marking expert security on all invisible fields

As different items might carry sensitive information, now the plugins highlights every atom item with the invisible flag set with an expert note in the security group. The "expert.group == security" filter now also works in older SAP GUI versions (700 and 710). Thanks Victor!
Fix GUI patch level string call
Updated example uses

Updated the filter for searching passwords or sensitive data in Dynt Atom items. As the attribute flag is now available in the filter, it's possible to filter for packet that contains "invisible" fields. Thanks Victor !