Support retrieval of properties

[ri0t1985]

Currently we dont support the retrieval of properties when using a CSS selector.

The only thing that IS supported is the "img" property, but that is hardcoded.

I recommend the following solution:

• Implement a new option that can be given to a selector: property
• the value for the option should be the property the user wishes to retrieve. e.g: "img"
• during parsing, check if the option "property" exists, and retrieve that property from the attribute.