Refactores primitive types in the API. Now int -> Integer and double -> Double.

This is to support Redis null values

src/test/java/redis/clients/jedis/tests/commands/StringValuesCommandsTest.java

@@ -173,6 +173,6 @@ public class StringValuesCommandsTest extends JedisCommandTestBase {
     @Test
     public void strlen() {
 	jedis.set("s", "This is a string");
-	assertEquals("This is a string".length(), jedis.strlen("s"));
+	assertEquals("This is a string".length(), jedis.strlen("s").intValue());
     }
 }