Fixed type signature of uninhabited method.

Added unit test to prevent similar mistakes from happening again. The
previous method was wrong because it dereferenced a pointer to a void type to
match on the result. No self pointer was needed, and the correct method
signature took the self value by value.
Issue #5967: Make rvalues mutable
Add explanatory comment to is_rvalue_or_immutable()
Allow static strings to be used with keyword checks
remove deriving_eq, deriving_iter_bytes, deriving_clone (deprecated in 0.6)
Merge type_span and type_def, and ditto with value_span and value_def
rename `at_vec::from_owned` and `at_vec::from_slice` to `at_vec::to_managed_consume` and `at_vec::to_managed`
Add unsetenv wrapper
Remove stray binary
add a Clone impl for borrowed pointers
auto merge of #6499 : dotdash/rust/static_keywords, r=thestinger
syntax: deprecate #[auto_{en,de}code] in favour of #[deriving({En,De}codable)].

Replace all instances of #[auto_*code] with the appropriate #[deriving] attribute
and remove the majority of the actual code, leaving stubs to refer the user to
the new syntax.
rustpkg: Reorganize test files
auto merge of #6500 : kud1ing/rust/cleanup, r=bstrie

Fixes #6445
rustpkg: ignore tests on i686, since they fail
allow constructing Rc/RcMut from Const types too
auto merge of #6501 : june0cho/rust/incoming, r=graydon

Fix #3783.
add DeepClone impl for @T and @mut T with T: Const
auto merge of #6502 : huonw/rust/no-auto-code, r=graydon

Replace all instances of #[auto_*code] with the appropriate #[deriving] attribute
and remove the majority of the actual auto_* code, leaving stubs to refer the user to
the new syntax.

Also, moves the useful contents of auto_encode.rs to more appropriate spots: tests and comments to deriving/encodable.rs, and the ExtCtxtMethods trait to build.rs (unused so far, but the method syntax might be nicer than using the mk_* fns in many instances).
auto merge of #6503 : sonwow/rust/at_vec-renamed, r=graydon

`str::from_slice` and `vec::from_slice` are changed to `str::to_owned` and `vec::to_owned`. (#6389)

Replace `at_vec::from_owned` and `at_vec::from_slice` with `at_vec::to_managed_consume` and `at_vec::to_managed`.