Bug#18875: Default value of tmp_table_size is meaningless
Bug#18875: Default value of tmp_table_size is meaningless

It makes no sense to have a default tmp_table_size larger than the 
max_heap_table_size .  In usage, the tmp is ever limited to the max value, 
so I lowered the default tmp to the default max value.

A great idea would be to emit a warning when the tmp_table_size is set to 
greater than max_heap_table_size .

natsys/mariadb_10.2,flynn1973/mariadb-aix,natsys/mariadb_10.2,davidl-zend/zenddbi,flynn1973/mariadb-aix,davidl-zend/zenddbi,ollie314/server,ollie314/server,natsys/mariadb_10.2,ollie314/server,natsys/mariadb_10.2,ollie314/server,natsys/mariadb_10.2,flynn1973/mariadb-aix,davidl-zend/zenddbi,natsys/mariadb_10.2,davidl-zend/zenddbi,flynn1973/mariadb-aix,davidl-zend/zenddbi,ollie314/server,ollie314/server,ollie314/server,slanterns/server,flynn1973/mariadb-aix,flynn1973/mariadb-aix,flynn1973/mariadb-aix,davidl-zend/zenddbi,flynn1973/mariadb-aix,davidl-zend/zenddbi,natsys/mariadb_10.2,flynn1973/mariadb-aix,ollie314/server,flynn1973/mariadb-aix,ollie314/server,ollie314/server,natsys/mariadb_10.2,davidl-zend/zenddbi,ollie314/server,davidl-zend/zenddbi,natsys/mariadb_10.2,flynn1973/mariadb-aix,natsys/mariadb_10.2,davidl-zend/zenddbi,natsys/mariadb_10.2,davidl-zend/zenddbi