Fixed some threading issues that Guilhem found (and its what I get for copy and pasting from elsewhere without thinking about it). Added depracted messages to BACKUP, RESTORE, and LOAD TABLE FROM MASTER (which doesn't work well). 


client/Makefile.am:
  Added threaded libary.
client/mysqlimport.c:
  Updated logic to use threaded libmysql correctly.
client/mysqlslap.c:
  Modified how threads were working.
mysql-test/r/backup.result:
  Added deprecated messages.
sql/sql_yacc.yy:
  Added deprecated messages to RESTORE, BACKUP, and LOAD TABLE FROM MASTER