Merge InnoDB-3.23.50

Decrease net_buffer_length to not get problems when running against mysqld with same max_allowed_packet

Fix for bug on intel where (int32) 1 << 32 == 1, which gave problems when using 32 keys.
Allow SET PASSWORD for anonymous user

Fix for --enable-local-infile
Portability fix for bison

  qsort implementation backported from 4.0 tree, the old one was buggy

into hundin.mysql.fi:/home/heikki/mysql

  If the string foreign was succeeded by a non-space character, that confused the foreign key syntax parser

  Add a warning to drop database wait if there are still open handles on a table

  Add some more safety if MySQL tries to drop a table on which there are open handles

  Try to make sure DROP DATABASE does not cause a deadlock because we now let InnoDB wait MySQL does not have open handles to tables we drop

  DROP DATABASE required that the database name is in lower case to work; put it always to lower case in innobase_drop_database