Re: SQL99, CREATE CAST, and initdb

I've gone ahead and committed patches for CREATE CAST/DROP CAST, as well
as for a few other SQL99 clauses in other statements. Details below...
                   - Thomas

Implement SQL99 CREATE CAST and DROP CAST statements.Also implement alternative forms to expose the PostgreSQL CREATE
FUNCTIONfeatures.
Implement syntax for READ ONLY and READ WRITE clauses in SET
TRANSACTION.READ WRITE is already implemented (of course).
Implement syntax for "LIKE table" clause in CREATE TABLE. Should be
fairlyeasy to complete since it resembles SELECT INTO.
Implement MATCH SIMPLE clause for foreign key definitions. This is
explicitSQL99 syntax for the default behavior, so we now support it :)
Start implementation of shorthand for national character literals inscanner. For now, just swallow the leading "N", but
sometimesoon let'sfigure out how to pass leading type info from the scanner to the
 
parser.We should use the same technique for binary and hex bit string
literals,though it might be unusual to have two apparently independent literaltypes fold into the same storage type.