DOC: Add include for library(persistency).  Boris Vassilev.
DOC: Add include for library(persistency).  Boris Vassilev.

edechter/swipl-devel,edechter/swipl-devel,edechter/swipl-devel,mndrix/swipl-devel,edechter/swipl-devel,jn7163/swipl-devel,jn7163/swipl-devel,mndrix/swipl-devel,edechter/swipl-devel,koryonik/swipl-devel,jn7163/swipl-devel,koryonik/swipl-devel,koryonik/swipl-devel,jn7163/swipl-devel,koryonik/swipl-devel,jn7163/swipl-devel,mndrix/swipl-devel,mndrix/swipl-devel,koryonik/swipl-devel,mndrix/swipl-devel