* Switch to "newtype" enums
* Exposed:
    - cl_set_clcb_msg()
    - cl_cvdparse() and supporting symbols
    - cl_debug()
    - DB load/progress callback setting functions
    - engine scan callbacks and types
    - File file inspection callbacks and types
* Moved allowlisted funcs/types/variables to constants
* Updated bindgen dependency

…y-and-authors

Update repository, authors, and copyright.

…epage-url

Correct homepage URL

…authors

Update authors

Merge the clamav-sys Rust crate into clamav, preserving history

Some builds using the tarball with the vendored Rust dependencies are
failing.

The onenote-rs dependency is presently tied to a git branch from github
rather than using a release from crates.io. This is the differing factor
though I'm unsure why it is causing the build to try to update the repo
rather than just building the vendored source.

This commit adds a `--offline` parameter to the build options if the
vendored source is detected, in an attempt to force Cargo to use what it
has and stay offline.

Export additional build context to Rust-based builds, and eliminate some of the
duplicated logic when bulding a macOS univeral binary.