Add IntoRawHandle impl for FFI ownership transfer

[RossSmyth]

Basically the inverse of FromRawHandle. Allows an FFI application to take ownership of the handle without leaking a String if constructed on the Rust side.

[sirhcel]

Thank you for this PR! Also providing IntoRawHandle looks like the right companion for AsRawHandle.

Allows an FFI application to take ownership of the handle without leaking a String if constructed on the Rust side.

Do you mean leaking COMPort::port_name (if present) when mem::forget-ting a COMPort for not closing it on drop?

[RossSmyth]

Yeah

[sirhcel]

Alright. Thank you! Could you please add a changelog entry for integrating?

[RossSmyth]

Done

[sirhcel]

Awesome! Thank you very much!