Procedure names were unintentionally case-sensitive when read from the database
(but case-insensitive when fetched from the cache).
Note that the DB-part of qualified names is still case-sensitive (for consistency
with other usage in mysql).
make characteristics (and SHOW) work right, we had to separate the old
definition blob in the mysql.proc table into separate fields for parameters,
return type, and body, and handle the characteristics (like SQL SECURITY)
separately... and then reassemble the CREATE string for parsing, of course.
This is rather ugly, mostly the parser bit. (Hopefully that will be better
with the new parser.)
New sp_cache C API. When an SP is dropped, old caches (in other threads)
become invalid and are cleared.
Also, the caches in THD are only created on demand.
