[1.2.X] Fixed #11907 -- EmailField now runs strip() on its input. This means...

[1.2.X] Fixed #11907 -- EmailField now runs strip() on its input. This means mistakenly including leading or trailing spaces will not cause a validation error, and clean() will remove those spaces. Thanks, krisneuharth and djansoft. Backport of [13997].

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.2.X@14124 bcc190cf-cafb-0310-a4f2-bffc1f526a37