Fix conflicting filename in build.
Merge pull request #49 from hannobraun/master

Add target to .gitignore
Merge pull request #52 from metajack/ambiguous-filename

Fix conflicting filename in build; rs=Ms2ger
Remove redundant "extern crate std"

This causes a compiler error on recent Rust versions.
Configure Git to ignore Cargo.lock

The lock file should not be checked into the repository for libraries.
Otherwise the locked versions therein could complicate the build for any
applications using the library.
Fix Cargo warning