Edition 5 update 3

Edition 5, third update

See http://www.jirka.org/diffyqs/changes.html for changes.

This version should be totally compatible with version 5.0, 5.1, and 5.2, and only includes very minor changes or errata fixes.

Edition 5 update 2

Edition 5, second update.

See http://www.jirka.org/diffyqs/changes.html for changes.

This version should be totally compatible with version 5.0 and 5.1, and only includes very minor changes or errata fixes