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/RedisPipeline.java

@@ -193,4 +193,8 @@ public interface RedisPipeline {
     Response<Long> zrevrank(String key, String member);
 
     Response<Double> zscore(String key, String member);
+
+    Response<Long> bitcount(String key);
+
+    Response<Long> bitcount(String key, long start, long end);
 }