Don't rely on include_path to include files.

Always use dirname() or, once available, ABSPATH.

props ketwaroo, hakre.
fixes #17092.


git-svn-id: http://develop.svn.wordpress.org/trunk@25616 602fd350-edb4-49c9-b593-d223f7449a82
Clean up the path calculations in wp::parse_request().

props evansolomon for initial cleanup.
fixes #22209.


git-svn-id: http://develop.svn.wordpress.org/trunk@25617 602fd350-edb4-49c9-b593-d223f7449a82
'sanitize_user' is a filter, not an action. fixes #25411.

git-svn-id: http://develop.svn.wordpress.org/trunk@25618 602fd350-edb4-49c9-b593-d223f7449a82
Simplify the login page viewport meta for mobile devices, so it's less restrictive on the user. Allows for developers to override if necessary via the `login_head` action. props azaozz. fixes #24777.


git-svn-id: http://develop.svn.wordpress.org/trunk@25619 602fd350-edb4-49c9-b593-d223f7449a82
Better error messaging on install.php. props DrewAPicture, ocean90. fixes #24982.


git-svn-id: http://develop.svn.wordpress.org/trunk@25620 602fd350-edb4-49c9-b593-d223f7449a82