string: implement strncat, strncmp, and strncpy

Test if the redox version compiles too

redox fixes

Add test.sh and fmt.sh to travis.yml

Do not accept unformatted code.

Finalize Aarch64 support

Update platform support for linux to avoid the use of syscalls not
supported by Aarch64.
  - link, chown, and open should use fchownat and linkat with fd
    set to AT_FDCWD.
  - use dup3 with the 3rd arg set to 0 instead of dup2.

Add cargo fmt script

Fix platform

 - Add a rustfmt config
 - Get the current code passing the formatter

Dan Robertson authored 7 years ago and Dan Robertson committed 7 years ago

 - Add cfg to extern crate sc. It is not used by redox.
 - Fix bad syntax in brk implementation for redox
 - nits
   - style: update brk implementation for linux
   - style: no space between not operator and ptr.is_null
   - style: should be a space around = in module path

implement some unistd