add IN/OUT instructions.

git-svn-id: https://insight.labri.fr/svn/trunk@868 00316523-1ed1-4fdc-9313-76483a3f41dc
add a label on nodes to indicate curren entrypoint.

git-svn-id: https://insight.labri.fr/svn/trunk@869 00316523-1ed1-4fdc-9313-76483a3f41dc
keep dot viewer centered on the PC

git-svn-id: https://insight.labri.fr/svn/trunk@870 00316523-1ed1-4fdc-9313-76483a3f41dc