removed unneccessary locale code

Hi there.

I was going through ddate.c, and I noticed that the locale includes and checks weren't really doing anything towards the functionality of the program. Furthermore, they were causing the build to fail on OS X (libintl.h isn't part of BSD's gettext). 

Just thought I could help to improve portability.
If the locale calls are performing some important check that I'm not aware of, please reject this pull. 

woodruffw