Decrement update count bubbles as plugins/themes are updated, live.

props gcorne, mitchoyoshitaka.
fixes #17703.

Built from https://develop.svn.wordpress.org/trunk@27280


git-svn-id: http://core.svn.wordpress.org/trunk@27136 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Remove title attributes on the fly when [27280] makes them incorrect. see #17703.

Built from https://develop.svn.wordpress.org/trunk@27281


git-svn-id: http://core.svn.wordpress.org/trunk@27137 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Ensure disabled secondary buttons do not change background on hover or active.

props helen.
fixes #26785.

Built from https://develop.svn.wordpress.org/trunk@27282


git-svn-id: http://core.svn.wordpress.org/trunk@27138 1a063a9b-81f0-0310-95a4-ce76da25c4cd