* release of groffer 0.9.13
* groffer.sh:
- first line: Add space to `#! /bin/sh'.
- $_VIEWER_DVI: Add `kdvi'.
- $_VIEWER_PDF: Add `kghostview', `ggv', and `kpdf'.
- $_VIEWER_PS: Add `kghostview' and `ggv'.
- $_modefile: For the output file name, add extension .ps for ps
mode and .dvi for dvi mode. This exists already for the html and
pdf modes.
- Update some parts of the documentation.
* README, README_SH:
- Move some parts on usage from README_SH to README.
- Reformulate several parts of both files.
* groffer.man: update