Remove rust_unwind.h

Adds the required definitions in the correct place.
Merge branch 'incoming' of git://github.com/mozilla/rust into unwind-fix
libstd: impl Integer for BigUint/BigInt.

Also remove abs() method from the non-trait impl for BigInt/BigUint.
That method is provided in the Signed trait.
libstd: inlining almost every methods in bigint module.
rand: Fix infinite recursion

`self` has type `&@Rand`, so `*self` will be of type `@Rand` which causes
this same impl to be called again.
auto merge of #6097 : Blei/rust/fix-rand, r=pnkfelix

`self` has type `&@Rand`, so `*self` will be of type `@Rand` which causes
this same impl to be called again.

Fixes #6061
change stage1,stage2,stage2 into not(stage0)

With luck, this will allow rust to compile itself without --cfg flags again...
refactoring mod.rs
parser comments only
refactor parse_fn_decl
comments, helper function for tests, more informative error message
adding parse_path
simplify, based on invariant that items_allowed != foreign_items_allowed
remove unnecessary function
reindent in parser
get rid of prec.rs

prec.rs no longer had much to do with precedence; the token->binop
function fits better in token.rs, and the one-liner defining the
precedence of 'as' can go next to the other precedence stuff in
ast_util.rs
parser comments

parser comments
refactoring to split foreign_items from items
undo abstraction over whether to parse attrs in a block

In principle, it seems like a nice idea to abstract over the two
functions that parse blocks (one with inner attrs allowed, one not).
However, the existing one wound up making things more complex than
just having two separate functions, especially after the obsolete
syntax is (will be) removed.
remove unused RESTRICT_NO_CALL_EXPRS restriction