Revamp doc index

Fixes #14972
Fixes type range issue during linting (#16684)

 - Ensures the propagated negation sign is properly utilized during type
   checking.
 - Removed redundant type checking, specifically regarding the out of bounds checking
   on a bounded type.
 - Closes #16684
Add ICE regression test for issue #16218.

This code used to produce an ICE on the definition of trait Bar
with the following message:

Type parameter out of range when substituting in region 'a (root
type=fn(Self) -> 'astr) (space=FnSpace, index=0)

Closes #16218.
Add regression test for issue #10766

This test verifies that casting from the same lifetime on a value
to the same lifetime on a trait succeeds. Closes #10766.
Fix vector/array/slice terminology in manual.

Fixes #16015.
Relicense shootout-reverse-complement.rs to the shootout license.

Everyone agreed.  Fix #17065
Relicense shootout-nbody.rs to the shootout license

Everyone agreed. fix #17073
Flip arguments to `std::iter::iterate`.

Breaks `iterate(f, seed)`, use `iterate(seed, f)` instead.
The convention is to have the closure last.

Closes #17066.

[breaking-change]
enable jemalloc debugging in unoptimized builds

The performance hit from these checks is significant, but unoptimized
builds are already incredibly slow. Enabling these checks results in
better test coverage since there are bots doing unoptimized builds, and
the cost is relatively small in the context of an unoptimized build.
This also allows using `JEMALLOC_FLAGS` to override the default
configure flags.
Fix casts in constant expressions

Fixes #17074.
Allow Rust to be built with LLVM trunk (3.6).
rustdoc: Don't strip #-lines if notrust

Other languages may not want to have a leading #-line get stripped.
libnative/io: generic retry() for Unix 64 bit read/write().

Win32/WinSock APIs never call WSASetLastError() with WSAEINTR
unless a programmer specifically cancels the ongoing blocking call by
a deprecated WinSock1 API WSACancelBlockingCall().
So the errno check was simply removed and retry() became an id function
on Windows.
Note: Windows' equivalent of SIGINT is always handled in a separate thread:
http://msdn.microsoft.com/en-us/library/windows/desktop/ms682541%28v=vs.85%29.aspx
"CTRL+C and CTRL+BREAK Signals"

Also, incidentally rename a type parameter and clean up some module imports.
Add ICE regression test with unboxed closures

This code used to produce the following ICE:

   error: internal compiler error: get_unique_type_id_of_type() -
   unexpected type: closure,
   ty_unboxed_closure(syntax::ast::DefId{krate: 0u32, node: 66u32},
   ReScope(63u32))

This is a regression test for issue #17021.
Relicense shootout-chameneos-redux.rs to the shootout license.

Everyone agreed. fix #17076
rand: inform the optimiser that indexing is never out-of-bounds.

This uses a bitwise mask to ensure that there's no bounds checking for
the array accesses when generating the next random number. This isn't
costless, but the single instruction is nothing compared to the branch.

A `debug_assert` for "bounds check" is preserved to ensure that
refactoring doesn't accidentally break it (i.e. create values of `cnt`
that are out of bounds with the masking causing it to silently wrap-
around).

Before:

    test test::rand_isaac   ... bench: 990 ns/iter (+/- 24) = 808 MB/s
    test test::rand_isaac64 ... bench: 614 ns/iter (+/- 25) = 1302 MB/s

After:

    test test::rand_isaac   ... bench: 877 ns/iter (+/- 134) = 912 MB/s
    test test::rand_isaac64 ... bench: 470 ns/iter (+/- 30) = 1702 MB/s

(It also removes the unsafe code in Isaac64Rng.next_u64, with a *gain*
in performance; today is a good day.)
rustc: use a TypedArena to allocate types in the type context.
rustc: fix fallout from the addition of a 'tcx lifetime on tcx.
rustc: fix fallout from the addition of a 'tcx lifetime on trans::Block.
rustdoc: fix fallout from the addition of a 'tcx lifetime on tcx.