Remove redundant memory management in nonstick::libpam; fix UB. - Uses the libpam-sys-helpers BinaryPayload / OwnedBinaryPayload structs to handle memory management and parsing for Linux-PAM binary messages. - Gets rid of the (technically) undefined behavior in PtrPtrVec due to pointer provenance. - Don't check for malloc failing. It won't, even if it does. - Formatting/cleanups/etc.

[package]
name = "libpam-sys-helpers"
version.workspace = true
authors.workspace = true
repository.workspace = true
edition.workspace = true
rust-version.workspace = true
license.workspace = true
readme = "README.md"

[dependencies]
libc = "0.2"

[build-dependencies]
libc = "0.2"