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
Added intristics
Fixups
No split stack on failure handlers
Patches for fresh rust
Silenced some warnings