should fail to create

The problem was that this type of errors was checked during view
creation, which doesn't happen when CREATE VIEW is a statement of
a created stored routine.

The solution is to perform the checks at parse time.  The idea of the
fix is that the parser checks if a construction just parsed is allowed
in current circumstances by testing certain flags, and this flags are
reset for VIEWs.

The side effect of this change is that if the user already have
such bogus routines, it will now get a error when trying to do

  SHOW CREATE PROCEDURE proc;

(and some other) and when trying to execute such routine he will get

  ERROR 1457 (HY000): Failed to load routine test.p5. The table mysql.proc is missing, corrupt, or contains bad data (internal code -6)

However there should be very few such users (if any), and they may
(and should) drop these bogus routines.


mysql-test/r/sp-error.result:
  Add result for bug#20953: create proc with a create view that uses
  local vars/params should fail to create.
mysql-test/r/view.result:
  Update results.
mysql-test/t/sp-error.test:
  Add test case for bug#20953: create proc with a create view that uses
  local vars/params should fail to create.
mysql-test/t/view.test:
  Add second test for variable in a view.
  Remove SP variable in a view test, as it tests wrong behaviour.
  Add test for derived table in a view.
sql/sql_lex.cc:
  Remove LEX::variables_used.
sql/sql_lex.h:
  Remove LEX::variables_used and add st_parsing_options structure and
  LEX::parsing_options member.
sql/sql_view.cc:
  Move some error checking to sql/sql_yacc.yy.
sql/sql_yacc.yy:
  Check for disallowed syntax in a CREATE VIEW at parse time to rise a
  error when it is used inside CREATE PROCEDURE and CREATE FUNCTION, as
  well as by itself.