Need to clear eofbit in the ifstream of the NativeFile before seekg

Hi, nice library. I'm using it to read a binary file and jumping back and forth using Seek.

For the NativeFile implementation, seekg() call was failing because the eofbit was set, so I added a call to m_Stream.clear() right before m_stream.seekg() and that worked.

Not sure if it's the best implementation but just a heads up.