Fix Issue Pulsar-Edit-Highlights#80

Rather than always setting the start point of the bottom line to the
second to last row, only do so if the selection on the last row is
empty.

Before, the last two rows would be underlined if anything on the last
row was selected, because the bottom line would start on the second to
last row and ended on the last row.

lib/highlight-line-model.coffee

@@ -69,8 +69,11 @@ class HighlightLineView
         bottomLine = selectionRange.copy()
 
         topLine.end = topLine.start
-        bottomLine.start = new Point(bottomLine.end.row - 1,
-                                     bottomLine.end.column)
+        if bottomLine.end.column == 0
+            bottomLine.start = new Point(bottomLine.end.row - 1,
+                                         bottomLine.end.column)
+        else
+            bottomLine.start = bottomLine.end
 
         style = atom.config.get "highlight-line.underline"