Fix warnings about #![crate_id]

This solves warnings about the use of the deprecated `#![crate_id]` attribute, as well as the deprecated `--crate-file-name` command line option. See rust-lang/rust@c3ef04be5589901e7f3d9428ebe8f1eb2bdca7e4 for details.

Note that this won't compile on the current master without #128 (or equivalent). I can rebase after a fix lands