Stupid ^M characters from mixed DOS/UNIX files

Lab 4 design document had some ^M characters that somehow had survived
from an earlier DOS/Windows version of the file.  Fixed.

doc/lab4design.txt

@@ -57,13 +57,20 @@ to write explanatory notes after your output.
 
 C1.  EXPLAIN SELECT * FROM cities WHERE population > 5000000;
 
-C2.  EXPLAIN SELECT store_id FROM stores, cities
     WHERE stores.city_id = cities.city_id AND
+C2.  EXPLAIN SELECT store_id FROM stores, cities
+     WHERE stores.city_id = cities.city_id AND
            cities.population > 1000000;
 
-C3.  EXPLAIN SELECT store_id FROM stores JOIN
                    (SELECT city_id FROM cities
                     WHERE population > 1000000) AS big_cities
                    ON stores.city_id = big_cities.city_id;
+C3.  EXPLAIN SELECT store_id FROM stores JOIN
+                    (SELECT city_id FROM cities
+                     WHERE population > 1000000) AS big_cities
+                    ON stores.city_id = big_cities.city_id;
 
-C4.  EXPLAIN SELECT store_id, property_costs
     FROM stores, cities, states
     WHERE stores.city_id = cities.city_id AND
-           cities.state_id = states.state_id AND
           state_name = 'Oregon' AND property_costs > 500000;
+C4.  EXPLAIN SELECT store_id, property_costs
+     FROM stores, cities, states
+     WHERE stores.city_id = cities.city_id AND
+           cities.state_id = states.state_id AND
+           state_name = 'Oregon' AND property_costs > 500000;
 
 D:  Extra Credit [OPTIONAL]
 ---------------------------