(mainly by backporting 5.5. changes)

mysql-test/suite/maria/t/distinct.test:
  Remove the test that requires SSL. One test case for a bug is enough.
sql/scheduler.cc:
  make it the same as in 5.5
storage/innodb_plugin/row/row0mysql.c:
  make it the same as in 5.5
storage/innodb_plugin/row/row0sel.c:
  make it the same as in 5.5
storage/xtradb/row/row0mysql.c:
  make it the same as in 5.5
storage/xtradb/row/row0sel.c:
  make it the same as in 5.5