Improve reported stack traces by creating a new SQLException where appropriate

Awesome tool. I'll soon blog about it on the jOOQ blog (http://blog.jooq.org). In return, I wonder if you mind adding a backlink to jOOQ similar to your existing backlink to JDBI to the README.md.

About the main pull request: I've run jOOQ's integration tests with JDBCLint and seen that a couple of statements / result sets are closed twice. In that case, I think it is better to create a new `SQLException` that will contain the stack trace of the second `close()` operation, instead of using the `final SQLException` member that contains the stack trace at the time of statement / result set construction. In my opinion, that member exception is only useful in the `finalize()` method, short of any reasonable alternative...