Update release notes for 1.0.0-alpha. (tensorflow#6747)

* Update release notes for 1.0.0-alpha.

* Add numpy compatibility to release notes.

Merge pull request tensorflow#6491 from gunan/patch

patches for 0.12.1 release.

Update cudnn version in instruction for mac gpu. (tensorflow#6407)

Update installation instructions for tensorflow-gpu. (tensorflow#6231)

* Update installation instructions for tensorflow-gpu.

* Update os_setup.md

Update release note for tensorboard (tensorflow#5916)

Merge pull request tensorflow#5503 from yifeif/r0.11

Reformat markdown.

Small header changes and a Doxygen tweak to shape the C++ API a bit b…

…etter. (tensorflow#5304)

Change: 135747447

(cherry picked from commit 120c3f1)

Temporarily remove tests that fail running with a single GPU. (tensor…

…flow#5100)

* Temporarily remove tests that fail running with a single GPU.

* Fix tags order according to buildifier

Merge pull request tensorflow#4690 from gunan/r0.11

Small fixes to RELEASE.md

Merge pull request tensorflow#4284 from caisq/r0.10-fixes

Cherry-picking r0.10 fixes