* Fixed leak of `Arc<SharedPool>` in `DecrementSizeGuard::cancel()`
* Renamed `PoolOptions::connect_timeout` to `acquire_timeout` for clarity.
* Fixed `/* SQLx ping */` showing up in Postgres query logs
* Made `.close()` a regular function that returns a `Future`
* Deleted deprecated method `PoolConnection::release()`
* Document why connection might be dropped if `Pool::acquire()` is cancelled
* Added connection metadata to pool lifecycle callbacks
* Improved guarantees for `min_connections`
* Fixed `num_idle()` to not spin forever at high load
* Improved documentation across the `pool` module
The provided callback doesn't need to be `'static`. It should be enough that it doesn't borrow anything from the `Connection` itself, even if it does borrow data from elsewhere.
* removes the lifetime from Row
* removes MySqlQueryAs, SqliteQueryAs, etc. (no longer needed)
* introduce query_scalar
* introduce Decode::accepts to allow overriding runtime type checking
per-type (replaces TypeInfo::compatible)
* introduce Encode::produces to allow overriding the encoded type per-value
* adds a lifetime to Arguments (and introduce the HRTB HasArguments)
to support zero-copy encoding with SQLite
* renames Database::RawBuffer to HasArguments::ArgumentBuffer
* introduce Connect::connect_with to provide an ConnectOptions type
explicitly to opt-out of connection string parsing
* introduce Value and ValueRef traits to allow decoding-deferred
extraction of values from Rows
* introduce Encode::encode_by_ref and change Encode::encode to take
by-value to try and re-use memory where possible
* use thiserror to generate sqlx::Error
* [!] temporarily removes query logging
* [!] temporarily removes transactions
* Allow `conn.fetch(" ... ")` to be called where `conn` is an owned Connection
* Executor::fetch -> RefExecutor::fetch_by_ref
* Executor::fetch_by_ref -> Executor::fetch
* Move `Connection::describe` to `Executor::describe`
* `Transaction` is no longer a `Connection`
* `Connection` has `Executor` as a super-trait again which greatly simplifies bounds
- Rename the existing trait to an internal RawRow trait
- Row is used for selecting a dyn and deferring pulling its values out till later
- FromSqlRow -> FromRow
