Minor Backspace Issue

The backspace was not completely debugged.  When backspacing at the beginning of the line, and the line was not reported yet because it was a new line (insert modification type), the modification type was suppose to be reset back to line changed type (see the Two Issues post from a few days ago).  However, the equality operator was used instead of the assignment operator, so it was actually resetting it.

[commit 13443cd8ce]