Changed MySQL backend so that it fails silently if rollback() isn't supported (the code catches NotSupportedError exception)
Changed MySQL backend so that it fails silently if rollback() isn't supported (the code catches NotSupportedError exception)

git-svn-id: 554f83ef17aa7291f84efa897c1acfc5d0035373@459 bcc190cf-cafb-0310-a4f2-bffc1f526a37

svn2github/django,svn2github/django,svn2github/django