Binary protocol support for JDBC

Hello,

I partially, and for "test", implemented retrieval data in binary mode
(instead of text mode) for some Jdbc2 types, because I see great performance
boost (25% - 50%) on implemented types I think about including this work to
main JDBC branch.

This should be done without problem, because I added binary parameter to
Connection and Datasources, so user can decide to use binary mode retrieve or
current text mode (default).
Currently I implemented retrieve of short, int, long, date and BigDecimal.
Other simple and basic types, used in typically application I will implement
shortly.

If you think that this could be interested patch, I will send it.

Kind regards,
Radosław Smogura