Drupal 7.20
Merge tag '7.20' into 7.x
Issue #1794012 by dcam, Crell,  Lars Toomre: Remove t() from asserts in database system tests
Issue #1792380 by theo_: Fixed DatabaseCondition not cloning SelectQuery value object.
Issue #1012620 by Berdir, kbasarab, YesCT: Fixed Unique key on date_formats().(format|type) is problematic for case insensitive collations.
Issue #1266572 by znerol, joshf: Fixed Workaround in UpdateQuery_sqlite() for affected rows count causes certain updates to be suppressed.
Issue #1923554 by David_Rothstein, pwolanin, mitron | alfaguru: Fixed New anti-DoS measure breaks for some file URIs.
Issue #1347914 by Albert Volkman, Lars Toomre, batigolix, NROTC_Webmaster, xjm, sven.lauer: Fix up API docs for Filter module
Issue #1916928 by Alexander Pyle, YesCT, twistor: Document that clickLink is case sensitive
Issue #1932354 by Alexander Pyle: Fix up documentation for image_scale()
Issue #1890754 by Berdir, pwolanin, tim.plunkett: [Tests] Private Images visible by url.
Issue #1934568 by David_Rothstein, pwolanin: Allow sites using the 'image_allow_insecure_derivatives' variable to have partial protection from the security issues fixed in Drupal 7.20.
Prepare Drupal 7.21 release.
Merge branch '7.20-hotfix' into 7.x

Conflicts:
	CHANGELOG.txt
	includes/bootstrap.inc
Issue #1848464 by scor | jneubert: Fixed Make RDFa markup upward compatible with RDFa 1.1.
Issue #1827136 by amatzies, patrickd, posulliv | earnie: Add severity index to watchdog table.
Issue #1475342 by iamEAP | Kasper Souren: Fixed D6->D7 upgrade: system_update_7007() fail.
Issue #1586542 followup by andypost: Workaround for an issue where system update #7061 fails due to a memory leak and can't be run again.
Issue #1751054 by borisbaldinger, Berdir, vomiand: Fixed serious documentation problem with the $name variable in taxonomy-term.tpl.php (incorrectly documented as being sanitized when in fact it is not).
Issue #1898314 by droplet | xjm: Rename $user to $account in WebTestBase::drupalLogin().