Accept stream input

[zlangner]

Currently it appears that this library supports byte[] and filepath inputs. It would be much more flexible if it also allowed for Stream input.

[Modest-as]

Hi, PDFium does not expose a way to pass streams to the unmanaged code. Similar issue : #45

[zlangner]

That is true but that doesn't mean the API layer of docnet can't. You could do what PDFiumSharp does and offer methods that take streams but resolve them into byte arrays before accessing the unmanaged code.