Make it possible to refer to custom Rule properties in prepare script

myrule.qbs:

import qbs
Rule {

    property var myProperty: "test"
}


Re-use of that rule:
myproject.qbs:

import "myrule.qbs" as MyRule
...
MyRule { myProperty: "1" }
MyRule { myProperty: "2" }
MyRule { myProperty: "3" }
MyRule { myProperty: "etc" }