FIXED: arg/3: accept attributed variable as first argument.  Michael Hendricks.
FIXED: arg/3: accept attributed variable as first argument.  Michael Hendricks.

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