Lwt_ppx 1.0.1, Lwt 3.2.1

Lwt 3.2.1 is released because it still packages lwt.ppx, a deprecated copy of package lwt_ppx, and the two packages should be kept in sync.

Deprecations

• All PPX options are deprecated and should not be used (#534).
• The [%lwt ...] PPX syntax should be replaced by Lwt.catch (#534).

Fixes

• Clean up PPX -help usage message output (#525, Zan Doye).

Miscellaneous

• More thorough testing (#512, #535, Joseph Thomas).
• Clarification of the C binding (#521, @cedlemo).