This allows for tunability of the following behaviors:
* Minimum flowbuffer capacity to use when parsing a new unit
* Threshold at which flowbuffer capacity is contracted back to the
minimum after parsing a complete unit and before parsing the next
* Maximum flowbuffer capacity to allow when parsing a given unit
Failed flowbuffer allocations due to reaching maximum capacity or any
other reason now throw ExceptionFlowBufferAlloc.
parsers.
This consists of two parts:
1. The generated Flow classes expose their flow buffers via a new
method flow_buffer().
2. Flow buffers get two new methods:
// Interface for delayed parsing. Sometimes BinPAC doesn't get the
// buffering right and then one can use these to feed parts
// individually and assemble them internally. After calling
// FinishBuffer(), one can send the uppper-layer flow an FlowEOF()
// to trigger parsing.
void BufferData(const_byteptr data, const_byteptr end);
void FinishBuffer();
