Kragen's err.h

I was porting boggle from NetBSD to Linux. It used several functions that weren't in my run-time library, evidently having been introduced in 4.4BSD.

They were useful little functions -- things I'd written myself more than once, usually under a different name, because they're very useful. So, instead of looking for some source code on the Net for them, I just quickly rewrote them myself.

Here's release 1.

Briefly, they're sort of like a C equivalent of the warn() and die() functions in Perl.

The original BSD versions print the program's name followed by a colon before anything else. Unfortunately, there's no portable way to do this, so these quick-and-dirty substitutes just print their own names.

All of them print newlines at the ends of their messages.