Merge pull request #453 from ebfe/fix-build-master

Fix build with rust master
Fix build as well as most deprecation warnings
fold: actually print out empty lines
seq: allow inputs to have a unary plus
sort: implement --reverse
Merge pull request #455 from Arcterus/deprecation

Fix build and other issues
Resurrect cargo build
cargo: don't use generated code
cargo: simplify uutils_cargo.rs
cargo: add mv,sort
cargo: add nproc
fix uutils_cargo.rs
cargo: fix uutils_cargo
cargo: add chmod
cargo: depend on rust-lang/time
cargo: fix time dependency
cargo: uutils find_equiv -> get