New Line Detection Correction

The next problem discovered occurred when a multiple line selection was replaced with less lines than the selection and the cursor was at the end of the line after the change.  The lines removed were not being reported as deleted, in fact nothing was reported.  This was in the same section of code as the first problem, but this time the problem was caused because the modified line is new flag was being set when it should not have been.

As described on March 6 (second paragraph), an earlier fix added a check if characters were added when the cursor is at the end of the line to set this flag.  However, for this case, both of these conditions were true, so that flag was wrongly set.

Instead of checking if characters were added (which catches some of the wrong conditions), the code was changed to check if lines were added to the document, which was accomplish by checking if the local net line count variable is greater than zero.  If lines were deleted, or no lines were deleted or added, then this flag is not set.

[commit dea0ef4951]