Use os.SameFile to compare if two descriptors are the same.
Use os.SameFile to compare if two descriptors are the same.

Remove the inode function which is unix specific.  The os package provides a
method that does what we really intended, that is to compare two descriptors to
see if the underlying file is the same.

This should allow the code to work under windows.

Fixes #135

google/mtail,google/mtail,SuperQ/mtail,SuperQ/mtail