Simplify the cursor-invalid code.  This shouldn't be a functionality
change, but it consolidates the tests for a "valid" page slot.  I
can't figure out why the tests were split into two parts (one set
done search didn't return an insert object , and the other done if
search returned an insert object but didn't find a visible update,
or search didn't return an insert object.  The test combination may
not be necessary, but it's not going to cost anything and should be
more resiliant to changes in the search routines.   Reference #1062.
The reason we were seeing leaf pages during our review/cleanup of the
newly created child pages was because the for loop was wrong, it should
have been "i = pindex->entries - SPLIT_CORRECT_2", that is, we should
ignore the first and last entries in the new parent page.  Remove any
adjustment of the for loop and process all of the parent page entries,
it's no slower and will avoid bugs if we ever change our policy on what
pages are left untouched in the parent.

Reference 63dd6b2.