Create / Analyze data wrapper to avoid clump of size/pointer

[dertseha]

Based on discussion #19 , analyze which functions could benefit from a removal of the size/pointer data clump, and then see how a data-wrapper could be introduced.

If an interface is introduced, add also convenience functions for

• "wrapping" an arbitrary size/pointer
• creating an allocated data for non-movable data (see also Check for runtime of memory & need of runtime.KeepAlive() #22)