Enhancements to how queries with bind values are stored internally and sent to

Enhancements to how queries with bind values are stored internally and sent to
the server.  Previously we allocated a new String object for the entire final
query we were sending to the database.  If you had a big query, or especially
if you had large bind values you ended up with essentially two copies in memory.
This change will reuse the existing objects and therefore should take 1/2 the
memory it does today for a given query.  This restructuring will also allow
in the future the ability to stream bytea data to the server instead of the current approach of pulling it all into memory.
I also fixed a test that was failing on a 7.2 database.
Also renamed some internal variables and some minor cleanup.

 Modified Files:
 	jdbc/org/postgresql/core/QueryExecutor.java
 	jdbc/org/postgresql/jdbc1/AbstractJdbc1Connection.java
 	jdbc/org/postgresql/jdbc1/AbstractJdbc1Statement.java
 	jdbc/org/postgresql/jdbc2/AbstractJdbc2ResultSet.java
 	jdbc/org/postgresql/jdbc2/AbstractJdbc2Statement.java
 	jdbc/org/postgresql/test/jdbc2/DatabaseMetaDataTest.java