direct clients to retry rather than failing permanently.
 *  New: Expose the framed protocol in `Connection`. Previously this would
    return the application-layer protocol (HTTP/1.1 or HTTP/1.0); now it always
    returns the wire-layer protocol (HTTP/2, SPDY/3.1, or HTTP/1.1).
 *  Fix: Permit the trusted CA root to be pinned by `CertificatePinner`.
 *  Fix: Silently ignore unknown HTTP/2 settings. Previously this would cause

  //
  // In the constructor of AbstractCatchingFuture, the delegate future is assigned to a field
  // 'inputFuture'. That field is non-final and non-volatile. There are 2 places where the
  // 'inputFuture' field is read and where we will have to consider visibility of the write
  // operation in the constructor.
  //

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re{content:"\f3bd"}.fa-lastfm:before{content:"\f202"}.fa-lastfm-square:before{content:"\f203"}.fa-laugh:before{content:"\f599"}.fa-laugh-beam:before{content:"\f59a"}.fa-laugh-squint:before{content:"\f59b"}.fa-laugh-wink:before{content:"\f59c"}.fa-layer-group:before{content:"\f5fd"}.fa-leaf:before{content:"\f06c"}.fa-leanpub:before{content:"\f212"}.fa-lemon:before{content:"\f094"}.fa-less:before{content:"\f41d"}.fa-less-than:before{content:"\f536"}.fa-less-than-equal:before{content:"\f537"}.fa-le...

* Provide flags to use etcd3 backed storage ([#24455](https://github.com/kubernetes/kubernetes/pull/24455), [@hongchaodeng](https://github.com/hongchaodeng))

### Other notable changes

* Fix hyperkube's layer caching, and remove --make-symlinks at build time ([#25693](https://github.com/kubernetes/kubernetes/pull/25693), [@luxas](https://github.com/luxas))