Also made the parsing and handling of SP characteristics
more general and extendable, and added a few ch:istics.


Docs/sp-imp-spec.txt:
  Updated spec with new schema.
Docs/sp-implemented.txt:
  Added info about ALTER and SHOW.
mysql-test/r/sp.result:
  Minor change in SHOW FUNCTION|PROCEDURE STATUS output.
scripts/mysql_create_system_tables.sh:
  New mysql.proc schema.
scripts/mysql_fix_privilege_tables.sql:
  New mysql.proc schema.
sql/lex.h:
  New lex words for SP characteristics.
sql/sp.cc:
  New mysql.proc schema.
  Also made the characteristics handling slightly more extendable.
sql/sp.h:
  Made the characteristics handling slightly more extendable.
sql/sp_head.cc:
  Made the characteristics handling slightly more extendable.
sql/sp_head.h:
  Made the characteristics handling slightly more extendable.
sql/sql_lex.h:
  Made the characteristics handling slightly more extendable.
sql/sql_parse.cc:
  Made the characteristics handling slightly more extendable.
sql/sql_yacc.yy:
  Made the characteristics handling slightly more extendable
  and made the parsing of characteristics more general, and
  added a few new dito. (LANGUAGE SQL, and [NOT] DETERMINISTIC
  for starters).