Make error messages a little less patronizing.

Currently if you try to login and are underage you get an error message like this:

Sorry, sweetie. This site is for users $minimum_age and over.

Can we change this to something that doesn't refer to the default user as sweetie? This doesn't really fit with all uses of this module.

While I realize that the message is wrapped in a t() function the default message should be more general for everyone's use.