Issue when using Template.instance() and Template.currentData()

[steph643]

Template.instance() and Template.currentData() behave incorrectly when used inside the isolateValue function.
See this StackOverflow discussion:
http://stackoverflow.com/questions/28605311/in-meteor-how-to-set-a-reactive-dependency-on-a-subpart-of-a-template-data-cont

[mitar]

See meteor/meteor#4494