Removed "<select expression> INTO <destination>" deprication.

This was done after discussions with Igor, Sanja and Bar.

The main reason for removing the deprication was to ensure that MariaDB
is always backward compatible whenever possible.

Other things:
- Added statistics counters, mainly for the feedback plugin.
  - INTO OUTFILE
  - INTO variable
  - If INTO is using the old syntax (end of query)

mysql-test/main/sp-big.result

@@ -77,8 +77,6 @@ select count(*) as cnt from (select id1 from t1 force index (primary) where id1
 set id1_cond = id1_cond + 1;
 end while;
 end//
-Warnings:
-Warning	1287	'<select expression> INTO <destination>;' is deprecated and will be removed in a future release. Please use 'SELECT <select list> INTO <destination> FROM...' instead
 insert t1 select seq, seq, 1, 1, seq, seq, seq from seq_1_to_2000;
 set @before=unix_timestamp();
 call select_test();