added #if directives to UIAlertView additions to support ARC

[justinamberson]

Dropped in to an ARC project and got 6 errors, so I added these types of statements

if __has_feature(objc_arc)

return alert;

else

return [alert autorelease];

endif

[drewish]

This no longer applies cleanly. It also doesn't fix all the ARC issues in the project.