- dropped routines should not show up in status
- error handling for non-existing routines

+ some cleanup.

Fixed various bugs: setting local variables to NULL, SELECT INTO var now actually
might work, SELECT INTO with not row now gives a "no data" warning (instead of
the "empty query" error), etc.
Updated test cases accordingly.

WL#1263: Support for the attributes COMMENT and SUID
         in CREATE/ALTER PROCEDURE/FUNCTION

(For multi-lingual support.)
Also fixed memory leak when aborting parsing for a duplicate cursor.

  - Duplicate parameters/variables, conditions and cursors (not allowed).
  - ITERATE in labelled BEGIN-END (not allowed).
  - Missing SQLSTATE [VALUE] keywords in CONDITION/HANDLER declaration (added).
  - Empty BEGIN-END (now allowed).
  - End label (now optional).

(updated) Protocol_cursor class.
Also did some bug fixes.

MySQL error codes as well.
(No UNDO HANDLERs yet, and no SIGNAL or RESIGNAL.)
WL#850

One test in subselect.test still wrong.
Had to reconstruct all errmsg.txt files completely, since auto-merge made
a mess of the lot. :-(

syntax errors in stored procedures.

This included bug fixes in the 4.1 protocol (actually send and receive the
server_status flags).

Fixes bug #280.

Changed another unecessary use of Item_string into LEX_STRING (in sp_pcontext).

Disabled queries in FUNCTIONs.