regex(3) test harness

build:	cc -o testregex testregex.c
help:	testregex --man
note:	REG_* features are detected by #ifdef; if REG_* are enums
		then supply #define REG_foo REG_foo for each enum REG_foo

Glenn Fowler <gsf@research.att.com>
AT&T Research

PLEASE: publish your tests so everyone can benefit