Housekeeping
Rename `preserve`->`serialize` (clearer)
Throw wrapped exception on connection errors
Add `utils/repeatedly*` and `utils/mapv*`
BREAKING: Remove `skip-replies`

This was a half-baked and ill-considered feature that interacts
poorly with manual pipeline control (`with-reply`, etc.) and doesn't
serve any important purpose since the addition of manual pipeline
control.

As an added benefit, its removal also speeds reply processing.

This is a breaking change, but hopefully won't affect a large number
of people since it was a pretty obscure feature anyway and was mostly
used internally.
Refactor Protocol API

* Improved reply parsing performance.
* Significantly improved performance of `remember` (now called `restore`) by
  removing hack that required a roundtrip to Redis server.
* Changed `with-replies` to behave as expected (FILO rather than FIFO).
* Fixed to work correctly with pipelining: `atomically`, `evalsha*`, `lua-script`.
* Added deprecated vars for backwards compatibility, incl. `skip-replies`.
Bump version (1.7.0)