Remove reference counting

[Berstanio]

Currently the GCHandler tries to keep count of the amount of references for the same pointer, so no double free occure. This was mainly introduced for address reinterpretation methods like StructPointer#asStackElement.
However, the counting of the pointer references is just way to slow. A better approach is, to be able to set a "parent" for a pointer. Only the parent pointer is registered to GC, but all childs are holding strong references to their parent.
This allows to keep the pointer allive, until all children are collected.