Log Message:
stagit: update to 0.9.3.

ChangeLog:

- Makefile improvements
- some README tweaks and rewording, reordering
- add OpenBSD unveil support
- small code-style white-space/newline
- style.css: highlight anchor ids, useful for linking highlighting lines
  in a diff
- improve includes, stagit-index does not need compat.h
- atom.xml: improve output format a bit