Fixed os:: and int:: not being in scope, changed io::println to println
Updated copyright year on shootout-binarytrees.rs
Changed shootout-chameneos-redux output to conform to the 'official' output format.
Added missing copyright notice to shootout-spectralnorm.
Fixed shootout-fasta.rs output
Updated shootout-fasta.rs copyright years, removed stuff that caused lint to complain.
Changed Arena API to make it usable once more.