COMPATIBILITY FIX: now share kit works also without adding it as subproject

I am not sure, if we should allow this. Adding shareKit as subproject is the way to go - all future updates are for free then. You can use it even in ARC project without any changes.

On the other side, if someone used shareKit in the past and dragged files, now needs to readd share kit as subproject. This fix allows to continue to use newest version without adding as subproject.

I am more inclining to force people readd ShareKit as subproject, as it is more future friendly for them.