Change line ending from DOS- to Unix-style.

Motivation:

We have inconsistent line endings at the moment: the Ontology metadata
file uses Unix-style line endings while the PaNET.csv file uses
DOS-style line endings.  It would be better if the PaNET repository was
consistent.

Moreover, Unix tools may convert DOS-style lines to Unix-style lines.
This results in large diffs, making it hard to see actual changes.

Modification:

Run the `dos2unix` command on the PaNET.csv.  This results in two
changes:

  * The line endings are updated from `\r\n` (`0x0d 0x0a`) to `\n`
  (`0x0a`)

  * The UTF BOM (a three-byte sequence at the file's beginning that is
  normally not visible) is removed.

Result:

More consistent choice of line ending.  Removal of potentially confusing
BOM.

Closes: #128