This patch adds support for zstandard compression to Kafka as documented in KIP-110: https://cwiki.apache.org/confluence/display/KAFKA/KIP-110%3A+Add+Codec+for+ZStandard+Compression. 

Reviewers: Ivan Babrou <ibobrik@gmail.com>, Ismael Juma <ismael@juma.me.uk>, Jason Gustafson <jason@confluent.io>