AST-1212 Use unique pointers to DPBuffer in AOFlaggerStep
Implement AOFlaggerStep::process(unique_ptr<DPBuffer>)
Uses unique_ptrs as well when accumulating and sending data to the next step. Also the AOFlaggerStep unit tests use unique_ptrs now.
Fixes a minor bug (range problem) when processing the remaining buffers in the finish()
function.
Edited by Bas van der Tol