MINOR: show PCRE version and JIT status in -vv

haproxy -vv shows build informations about USE flags and lib versions.
This patch introduces informations about PCRE and the new JIT feature.
It also makes USE_PCRE_JIT=1 appear in the haproxy -vv "OPTIONS".

This is useful since with the introduction of JIT we will see libpcre
related issues.