Remove links_recently_updated_time (hardening).

Merges [27917] from the 3.8 branch to 3.7 branch.

see #27649.

Built from https://develop.svn.wordpress.org/branches/3.7@27919


git-svn-id: http://core.svn.wordpress.org/branches/3.7@27749 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Update Plupload Silverlight binary to 1.5.8 in the 3.7 branch.

Built from https://develop.svn.wordpress.org/branches/3.7@27921


git-svn-id: http://core.svn.wordpress.org/branches/3.7@27751 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Background Updates: Record plugin & theme update statistics like we do for core updates.

Pass plugin/theme update objects into the Background updater for consistency with core & translations.

Merges [27905] to the 3.7 branch.

props dd32.
fixes #27633.

Built from https://develop.svn.wordpress.org/branches/3.7@27924


git-svn-id: http://core.svn.wordpress.org/branches/3.7@27754 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Background Updates: Fix a PHP Warning caused by a Upgrader instance being passed into the Theme & Plugin $extra_stats parameter.
Background Updates: Fix two variable typos in r27905

Merges [27906],	[27928]	to the 3.7 branch.
Fixes #27633.

Built from https://develop.svn.wordpress.org/branches/3.7@27930


git-svn-id: http://core.svn.wordpress.org/branches/3.7@27760 1a063a9b-81f0-0310-95a4-ce76da25c4cd