switch field privacy as necessary

Struct fields are now private by default.
remove RefCell::get and RefCell::set

Rust PR #13301
c_types: allow lowercase type identifiers
use new proc bounds syntax

Changed in Rust 0.11-pre
test: change attribute syntax
use uint in byteswapping routines to sync with rust internals
Implement sized lang-item
Add support for range iterators
Simplify num.rs
Add size_hint for Range
Implement DoubleEndedIterator for Range
Update for latest Rust and add some inlines
Remove warning
Merge branch 'range_iters'