ocaml-sqlexpr 0.9.0

• migrate to jbuilder, move the PPX and Camlp4 extensions to separate packages
  ppx_sqlexpr and pa_sqlexpr (Freyr).
• fix stack overflows when iterating/fold/selecting over many rows when
  using Sqlexpr_concurrency.Id concurrency.
• multiple fixes to work with newer versions of Lwt and lwt_ppx.

Backwards compatibility is provided for the time being as follows:

• sqlexpr depends on ppx_sqlexpr, and a sqlexpr.ppx alias is provided
• if estring was installed (required if sqlexpr.syntax was being used),
  sqlexpr.syntax will also be installed
• installing pa_sqlexpr will also install its estring dependency, and
  cause a sqlexpr rebuild, so that sqlexpr.syntax is provided

These mean that it is still possible to (wherever it was before) compile e.g.
with

ocamlfind ocamlopt -package sqlexpr,sqlexpr.syntax -syntax camlp4o -c ...

but in the future the sqlexpr.syntax and sqlexpr.ppx aliases will be dropped,
so it is recommended to:

1. opam install ppx_sqlexpr and/or pa_sqlexpr explicitly
2. start using the ppx_sqlexpr instead of sqlexpr.ppx and pa_sqlexpr instead
   of sqlexpr.syntax in your build system.

Supported OCaml releases: 4.02 to 4.06.
Not presently installable on 4.07 because the ppx_core dependency isn't either.

0.8.0

• make camlp4 syntax extension optional (Josh Allmann)
• remove usage of camlp4 syntax extensions in internals (Simon Cruanes, Josh Allmann)

OCaml versions supported: 4.02.0 to 4.05 (tested with +beta2).