2.1.1-incubating

This release fixes issues reported for 2.1.0-incubating.

• #2473 - Downgrading ZK to stable version 3.4.13
• #2219 - Cpp client: add PatternMultiTopicsConsumerImpl to support regex subscribe
• #2387 - Fixed race condition during expansion of concurrent open hash maps
• #2348 - Fix NPE when splitting and unloading bundle
• #2223 - fix bug in FunctionRuntimeManager involving not cleaning up old invalid assignments
• #2367 - [compaction] make topic compaction works with partitioned topic
• #2203 - Make sure schema is initialized before the topic is loaded

The complete list of changes can be found at:

https://github.com/apache/incubator-pulsar/milestone/17?closed=1