The method select_insert::send_error does two things, it rolls back a statement
being executed and outputs an error message. But when a 
nonexistent column is referenced, an error message has been published already and
there is no need to publish another.
Fixed by moving all functionality beyond publishing an error message into 
select_insert::abort() and calling only that function.


mysql-test/r/errors.result:
  Bug#28677: test result
mysql-test/t/errors.test:
  Bug#28677: test case
sql/sql_class.h:
  Bug#28677: overriding abort()
sql/sql_insert.cc:
  Bug#28677: 
  - moved everything beyond producing an error message out of select_insert::send_error 
  and into new override select_insert::abort() 
  - made corresponding move of code from select_create::send_error to select_create::abort
sql/sql_select.cc:
  Bug#28677: No need to pusblish an error here