'CREATE TABLE IF NOT EXISTS ... SELECT' behaviour
BUG#55474, BUG#55499, BUG#55598, BUG#55616 and BUG#55777 are fixed
in this patch too.

This is the 5.1 part.
It implements:
- if the table exists, binlog two events: CREATE TABLE IF NOT EXISTS
  and INSERT ... SELECT

- Insert nothing and binlog nothing on master if the existing object
  is a view. It only generates a warning that table already exists.


mysql-test/r/trigger.result:
  Ather this patch, 'CREATE TABLE IF NOT EXISTS ... SELECT' will not
  insert anything if the creating table already exists and is a view.
sql/sql_class.h:
  Declare virtual function write_to_binlog() for select_insert.
  It's used to binlog 'create select'
sql/sql_insert.cc:
  Implement write_to_binlog();
  Use write_to_binlog() instead of binlog_query() to binlog the statement.
  if the table exists, binlog two events: CREATE TABLE IF NOT EXISTS
  and INSERT ... SELECT
sql/sql_lex.h:
  Declare create_select_start_with_brace and create_select_pos.
  They are helpful for binlogging 'create select'
sql/sql_parse.cc:
  Do nothing on master if the existing object is a view.
sql/sql_yacc.yy:
  Record the relative postion of 'SELECT' in the 'CREATE ...SELECT' statement.
  Record whether there is a '(' before the 'SELECT' clause.