bug#21757: md5sum: Accept different line endings in .md5 files

[MI]

Currently, "md5sum -c" gives a cryptic error when the line endings in the .md5 file 
are not LF (\x0A). It would be helpful if md5sum would just "do the right" and 
understand the 2 other newline standards.

.md5 files created on non-Unix systems may use line endings other than LF . Windows 
uses CRLF (\x0D\x0A), and maybe some Mac utility still uses CR (\x0D).

The error message is cryptic in a Linux terminal with CRLF files, because it 
overwrites the file name, since it just prints out the CR character:

    $ md5sum -w -c Some_File_From_Windows.md5
    : No such file or directoryWindows.mxf
    : FAILED open or readndows.mxf
    md5sum: WARNING: 1 listed file could not be read