Fixed eval bug; now conditions with local variables work in WHILE et al.
Made mysql_install_db.sh create proc table.


scripts/mysql_install_db.sh:
  Added creation of the mysql.proc table.
  Note: The table format will change later, right now it's rather minimalistic,
  just so things can be tested (and the database can easily be recreated when
  I break it :-/ ).
sql/item.h:
  Removed unused method.
sql/sp_head.cc:
  Added collection of called procedures in a list.
  Fixed eval bug; now conditions with local variables work in WHILE et al.