Conflicting plugins: add Related Posts plugins to the list

See #170 for more details
Tiled Galleries: use alt value instead of title for alt attribute

I added alt attributes to Tiled Galleries in e75fecaa818a3c84fcc9b64e729fe300bad869c0
but should have use the actualy image alt instead of the image title
Make backspace in carousel view functional in Chrome and Firefox.

Currently, utilize backspace will cause the page URL to update properly, but the actual image does not change. This corrects this behavior in Chrome and Firefox on Windows and OS/X--pressing backspace will now return to the previous image, as expected.
Display Posts widget: close div when no posts are returned

Props @chriswallace
Merge pull request #208 from jeherve/2152-trac

Display Posts widget: close div when no posts are returned
Merge pull request #203 from pcrumm/correct-backspace-behavior

Make backspace in carousel view functional in Chrome and Firefox.
Merge pull request #193 from jeherve/tiled-alt-images

Tiled Galleries: use alt value instead of title for alt attribute
Merge pull request #192 from jeherve/170-github

Conflicting plugins: add Related Posts plugins to the list
Jetpack: Slideshow: Properly resolves and closes #180
Revert "G+ Authorship: Restore the Google+ link at the bottom of the posts."

This reverts commit 67bffe6f4668ff56002ec0608eef264a01ba22f5.

@lezama indicated that he does not know why the changes in 67bffe6f466 were
made, so they are being reverted for consistency with wpcom.
Random redirect: Less fragile detection of the homepage

This merges r88927-wpcom.
Jetpack: Multisite: Fixed redirect while in Network Admin to stay in Network Admin
SSO: Switch from adding to general options

Instead use a Jetpack options page.
Merge branch 'master' into 2.9