Delete more unnecessary et-al-subsequent statements

 * if at any node (et-al-min == et-al-subsequent-min && et-al-use-first == et-al-subsequent-use-first) then delete the two subsequent attribute
 * some automatic detection and correction with a perl script, but also some manual edits still needed
 * continuation of #1109 and #1111
Merge pull request #1112 from zuphilip/sweep-et-al-subsequent

Delete more unnecessary et-al-subsequent statements