Add some permission and misc (mostly 'mode_t' related) constants to Redox.
Add some permission and misc (mostly 'mode_t' related) constants to Redox.

rust-lang-nursery/libc,rust-lang/libc,rust-lang-nursery/libc,cactorium/libc,cactorium/libc,cactorium/libc,rust-lang/libc,rust-lang-nursery/libc,rust-lang/libc