Transmuting from an immutable to a mutable reference is undefined
behavior in Rust, with the exception of UnsafeCell which tells the
optimizer to not draw too many conclusions. Sadly UnsafeCell::get cannot
yet be used in statics (see https://github.com/rust-lang/rust/issues/51718),
so this works around that by making the statics into functions and
making C macros to call those.

Add empty locale functions

See merge request redox-os/relibc!135

Add scanf

See merge request !134

sys_wait: implement C macros properly

See merge request redox-os/relibc!133

Remove the broken Rust functions and instead provide C macros in a
`include/bits` header. The C macros were taken from musl.

Fix compilation error in `sys_wait`

See merge request redox-os/relibc!132

Add `sys_wait` functions (Fixes #81)

Closes #81

See merge request redox-os/relibc!131

Update `platform::rawfile`

Make functions taking raw pointer return &'a instead of &'static

Simplify cstr_from_bytes_with_nul_unchecked()

The original implementation is modified from the `Cstr` method, but the
complexity there exists because it is trying to convert to the DST `Cstr`.

This is technically more correct, and matches the pointer methods in the
standard library.

Update ralloc. Closes GH-83.