Remove all uses of the legacy scheme syntax"

redox-rt/src/lib.rs

redox-rt/src/proc.rs

redox-rt/src/thread.rs

src/header/pty/redox.rs

src/header/stdlib/mod.rs

src/header/sys_mman/mod.rs

src/ld_so/mod.rs

src/platform/redox/epoll.rs

src/platform/redox/event.rs

src/platform/redox/exec.rs

src/platform/redox/extra.rs

src/platform/redox/mod.rs

src/platform/redox/ptrace.rs

src/platform/redox/signal.rs

src/platform/redox/socket.rs