Moved create/find/drop functions to a separate files (sp.cc,sp.h).

Fixed backpatching of forward jumps.
Implemented LOOP, WHILE, REPEAT (temporarily known as SPREPEAT).

Known bug: Expression evaluation still not quite ok (e.g. "x > 0"),
which is why IF and CASE is not yet implemented.

sql/sql_parse.cc

@@ -28,6 +28,7 @@
 #endif
 
 #include "sp_head.h"
+#include "sp.h"
 
 #ifdef HAVE_OPENSSL
 /*