[SPDK] [Release] 20.04: SPDK Top, IDXD, NVMe qpair groups

On behalf of the SPDK community I'm pleased to announce the release of SPDK 20.04!

This release contains the following new features:

- SPDK Top: Added application to allow users to monitor resource consumption by a running SPDK application.
- NVMe qpair groups: Added API to allow for pooling of NVMe qpairs across a single entity.
- OCF: Added support for OCF v20.03.
- Crypto bdev: Added support for AES_XTS for the QAT polled mode driver.
- IDXD: Added support for IDXD as an accel plug-in module allowing for use with the generic accel framework API. This feature is considered experimental.

Note: Legacy INI style configuration for SPDK applications has been deprecated and will be removed in a future release. Please switch to JSON-RPC configuration files and/or RPC driven run-time configuration.

The full changelog for this release is available at:
https://github.com/spdk/spdk/releases/tag/v20.04

This release contains 989 commits from 43 authors with over 61k lines of code changed.

We'd especially like to recognize all of our first time contributors:

	Allen Zhu
	Charles Machalow
	Maciej Szczepaniak
	Michał Berger
	Sudheer Mogilappagari
	Sylvain Didelot
	Xiaohui Zhu

	
Thanks to everyone for your contributions, participation, and effort!

Thanks,
Tomek