Drizzle JDBC 0.6

I just pushed up Drizzle JDBC 0.6 to the maven repo, should be in the central repository real soon.

Biggest changes:

• Fix setObject, handle null properly
• Fix bug 501443
• Fix bug 501452
• Default to MySQL protocol when connecting to Drizzle
• Remove unused code
• Default to single-threaded operation
• Rename org.drizzle.jdbc.Driver to org.drizzle.jdbc.DrizzleDriver
• Lots of protocol performance improvements - both faster and uses less memory (YourKit rules!)
• Prepared statement performance increased alot - uses less memory and is faster