Documentation a bit confusing about the Connection pool_* attributes

[kkalev]

When reading the documentation about the Connection object, one is led to believe that the pool_size, pool_lifetime, pool_keepalive attributes can be used with a ServerPool, regardless of the client_strategy used.

Yet looking into the code, it is clear that this functionality is only available when the REUSABLE strategy is used.

The documentation should be updated to make that point a bit more clear.

Thank you for a very helpful product.