Prepare bundled themes for 4.7

[davidakennedy]

Update changelogs, bump versions, check ZIPs, testing. And don't forget Twenty Sixteen.

Ticket for 4.5: #36354
Ticket for 4.6: #37426

Handbook page: ​https://make.wordpress.org/core/handbook/about/release-cycle/update-bundled-themes/

[davidakennedy]

Here are the possible/likely changelogs based on the commits after 4.6.

Twenty Seventeen

• Double check and update readme for release. Create changelog page.

Twenty Sixteen

No major changes, so a new version doesn't need to be released.

Twenty Fifteen

• Add documentation to filters in themes. See: #38382.
• Add preconnect to fonts.gstatic.com. See: #37171.

Twenty Fourteen

• Add preconnect to fonts.gstatic.com. See: #37171.
• Adds new styles to help positioning of Customizer edit shortcuts. See: #27403 and #38651.

Twenty Thirteen

• Add preconnect to fonts.gstatic.com. See: #37171.

Twenty Twelve

• Add preconnect to fonts.gstatic.com. See: #37171.

Twenty Eleven

No major changes, so a new version doesn't need to be released.

Twenty Ten

No major changes, so a new version doesn't need to be released.

[davidakennedy]

Changelogs updated:

​https://codex.wordpress.org/Twenty_Twelve_Theme_Changelog
​https://codex.wordpress.org/Twenty_Thirteen_Theme_Changelog
​https://codex.wordpress.org/Twenty_Fourteen_Theme_Changelog
​https://codex.wordpress.org/Twenty_Fifteen_Theme_Changelog

I'll change the dates later, if need be.

I created a page for Twenty Seventeen:

​https://codex.wordpress.org/Twenty_Seventeen_Theme_Changelog

[davidakennedy]

Default Themes: Bump version numbers and update readme files. Also updates description for Twenty Seventeen and removes version number for HTML5 shiv for easier updates in the future.

[davidakennedy]

Worth noting that I tested the handful of changes in default themes on older versions of WordPress back to 4.1 and didn't see any regressions as a result of enhancements and bug fixes this release.

[davidakennedy]

In 39496:

Default Themes: Update version numbers and readme files for 4.7 release

Bump version numbers and update readme files for themes with changes. Also updates description for Twenty Seventeen and removes version number for HTML5 shiv for easier updates in the future.

Props davidakennedy.

Fixes #38858.

[ocean90]

In 39498:

Default Themes: Update version numbers and readme files for 4.7 release

Bump version numbers and update readme files for themes with changes. Also updates description for Twenty Seventeen and removes version number for HTML5 shiv for easier updates in the future.

Merge of [39496] to the 4.7 branch.

Props davidakennedy.
See #38858.