Add site license language to icons' title

 
 <footer>
 <p><a href=http://creativecommons.org/licenses/by-nc-sa/4.0 target=_blank
-rel="license noopener noreferrer" style=display:inline-block
-title="Attribution-NonCommercial-ShareAlike 4.0 International"><img
+rel="license noopener noreferrer" style=display:inline-block title="content licensed
+Attribution-NonCommercial-ShareAlike 4.0 International unless otherwise noted"><img
 class=cc src=/static/cc.svg> <img class=cc src=/static/by.svg> <img
 class=cc src=/static/nc.svg> <img class=cc src=/static/sa.svg></a><br>
 <small><a class=systemtext href=/system