Exiv2::DataBuf cannot be initialised with data. #15
Description
One of the Exiv2::DataBuf constructors has parameters const byte *pData, size_t size.
https://exiv2.org/doc/structExiv2_1_1DataBuf.html
This is not usable from Python at present, and needs to be converted to take any simple buffer object such as Python bytes.
See discussion #14 for an example where this is needed.