Added bitcount to standard interfaces and bitop to MultiKey interfaces (since it is non-shardable)

Merge branch 'impl-bitcount-and-bitop' of git://github.com/koron/jedis

Conflicts:
	src/main/java/redis/clients/jedis/JedisCommands.java

src/main/java/redis/clients/jedis/JedisCommands.java

@@ -206,4 +206,8 @@ public interface JedisCommands {
     String echo(String string);
 
     Long move(String key, int dbIndex);
+
+    Long bitcount(final String key);
+
+    Long bitcount(final String key, long start, long end);
 }