papyrus now works with stable rust! 🎉

rustup default stable
cargo install papyrus

• Added the .cancel and .c commands which allow users to cancel out of the current input. This lets you exit more input loops if a leading closing bracket was defined.

• Turned off colouring for Windows, not yet working as intended.

• Added a version query to crates.io. When the repl is run interactively it will check the version number and print if there is a later version available.
• Added query() method to query papyrus version on crates.io.

• Added in benchmarks.

• Updated .travis.yml to initiate code coverage.

• First pass refactoring towards library stablisation.
• Added ExternCrate support. You can now use extern crate crate_name as alias;. This will work in most cases, please raise a PR if it doesn't.
• Compilation status is redirected to the console.
• Panics now get shown, and statements won't be added if code panics.