ieb/sparsemapcontent — pull request #156 by zathomas (2012-01-26 23:34:40+00:00)
Title: stop JDBCStorageClient from being destroyed when it is released to pool

calling `close()` on `JDBCStorageClient` when it is released back to the `JDBCStorageClientPool` makes it fail validation, so the pool destroys it.

The result is that no `JDBCStorageClient` is used more than once, which defeats the purpose of using a pool.

You can prevent the destruction by turning off `test-on-borrow` and `test-on-return` in configuration, but then the pool will be handing out instances that can't be used because `checkClosed()` will throw an exception.