Repeat fix + functionality extended

[mvantzet]

• Repeat now re-uses the existing DOM parent element instead of replacing the to-be-repeated item with a DIV. This allows us to e.g. repeat a "tr" inside a "table". Not sure if this will break anything though.
• After creating the repeated elements, attach event handlers to these new elements specifically so that changes are propagated automatically.
• Added the possibility to dynamically evaluate JS inside a repeating element, syntax: $${code}, e.g. $${key + 1} will render the list items 1, 2, .. (To make calculation easier I'm now converting the array 'key' (index) to an int)

[mvantzet]

Just realized that the change can break existing code in case the repeated element's parent already has e.g. a "way-scope" attribute, closing this PR for now.

[zjtnumber2]

This is a problem that can not be ignored. Have you solved it ?