We don't need because this file just have one called function and just in one place.
So, integrate this into mathmlexport and kill this file.

Also remove some useless comments.

Change-Id: Ia5749418d74c89be3d70dd5997fb90e1accf7f9e
Reviewed-on: https://gerrit.libreoffice.org/5431Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>