Only use lentic-this/that for access.

Previously I was accessing slots directly, but this breaks some of the
code in lentic-delayed which overrides the lentic-this/that methods.
A more testable lentic-delayed
Autoload added.
lentic-delayed loaded during test.
Examples all updated to be self-describing.
Update for all examples.
Quieten test.
Simple delete test.
kill line, erase buffer test.