A "fix" for problem discovered in BUG#8510: remove ONLY_FULL_GROUP_BY mode from ANSI mode, as currently
ONLY_FULL_GROUP_BY mode is overly restrictive.


mysql-test/r/ansi.result:
  A "fix" for problem discovered in BUG#8510: remove ONLY_FULL_GROUP_BY mode from ANSI mode.
mysql-test/t/ansi.test:
  A "fix" for problem discovered in BUG#8510: remove ONLY_FULL_GROUP_BY mode from ANSI mode.
sql/set_var.cc:
  A "fix" for problem discovered in BUG#8510: remove ONLY_FULL_GROUP_BY mode from ANSI mode.