#144 blank line added to large databases when new record cancelle

[Nathan Kurz]

If you have a large database (presumably one greater
than AUTO_RETAIN_SIZE (200)) a blank line will be added
at the bottom of the list view if the new record button
is clicked but no record is saved. Multiple lines for
multiple times.

These lines seem pretty harmless, and go away whenever
the grid is redone (on a sort, switch of database,
etc). This bug seems like it has existed unreported
for a good while, so it's probably safe to ignore for a
while longer.

The right solution here is probably going to involve
combining the code paths for the small and large
databases, so that they are handled the same. Adding
another special case to solve this small problem
doesn't seem worthwhile right now.