Optimize stack allocations in marshaler

[jasper]

Marshaled input arguments of variable are currently allocated of the heap.

For input arguments (that will not change), this can be optimized by using constant wrappers around the data, and allocate the actual data on the stack memory (extern the StackAllocate? block to fit the input data).

For output argument, the marshaler could use some form of buffering of COBIA data implementations (e.g. a pool of CapeArrayRealImpl? objects).