Breakage on trunk head due to PCRE

[Jim Jagielski]

./configure: line 6194: with_pcre: command not found
checking for -pcre2-config... no
checking for -pcre-config... no
checking for pcre2-config... no
checking for pcre-config... no
configure: error: pcre(2)-config for libpcre not found. PCRE is required and 
available from http://pcre.org/
make: *** No targets specified and no makefile found.  Stop.