WL#2787 (Add view definer/owner to the view definition (.frm) to check privileges on used tables and stored routines when using a VIEW.)
Part 2 postreview fixes.


sql/ha_innodb.cc:
  Renamed structure st_security_context to class Security_context
sql/item_func.cc:
  Renamed structure st_security_context to class Security_context
sql/item_strfunc.cc:
  fixed USER() function
sql/log.cc:
  variable used to optimize access to security context
sql/mysql_priv.h:
  Renamed structure st_security_context to class Security_context
sql/mysqld.cc:
  main security context used direcly
sql/sp_head.cc:
  Renamed structure st_security_context to class Security_context
  removed unneed variable
sql/sp_head.h:
  Comment inmroved
  Renamed structure st_security_context to class Security_context
sql/sql_acl.cc:
  Renamed structure st_security_context to class Security_context
  fixed function comment and return value
  variable used to optimize access to security context
  Renamed method of Security_ontext
sql/sql_acl.h:
  fixed return value type
sql/sql_class.cc:
  Renamed structure st_security_context to class Security_context
sql/sql_class.h:
  Renamed structure st_security_context to class Security_context
  Method renamed
sql/sql_db.cc:
  Renamed structure st_security_context to class Security_context
  fixed layout
sql/sql_parse.cc:
  registration of wanted access for underlying tables
sql/sql_show.cc:
  Renamed structure st_security_context to class Security_context
  fixed layout
sql/sql_yacc.yy:
  Renamed structure st_security_context to class Security_context