[1.4.x] Bump version post-release.
[1.4.x] Fixed typo in docs/releases/1.4.9.txt.

Backport of 3b0293370a from master
Fixed SyntaxError on Python 2.5 caused by a @unittest.skipIf class decoration.
Merge pull request #1837 from loic/django14

Fixed SyntaxError on Python 2.5 caused by a @unittest.skipIf class decoration.
Fixed #21362 -- Restored Python 2.5 compatibility.
[1.4.x] Bump version info and add release notes for 1.4.10.
Merge remote-tracking branch 'upstream/stable/1.4.x' into nonrel-1.4