Updating HAProxy snapshot documentation v1.5.7 generated by haproxy-dconv v0.3.1-23

0539ba3 [RELEASE] Released version 1.5.7
Updating HAProxy stable documentation v1.5.7 generated by haproxy-dconv v0.3.1-23

0539ba3 [RELEASE] Released version 1.5.7
42a3e20 MINOR: ssl: add statement to force some ssl options in global.
b3cc425 MINOR: ssl: add fetchs 'ssl_c_der' and 'ssl_f_der' to return DER formatted certs