Add line missing line ending.

When reassembling the lines, no line ending were added to the last line, even if the selection ended with a line ending character.
This caused the following line to be pulled up unto the last line of the selected block.

SortNumerically.py

@@ -29,4 +29,8 @@ def run(self, edit):
 
             output = line_ending_character.join(sorted_lines)
 
+            # If the end of the region had a line ending character, we re-add it here
+            if self.view.substr(region).endswith(line_ending_character):
+                output += line_ending_character
+
             self.view.replace(edit, region, output)