rustc: Run destructors when dest=Ignore

Previously, if statements of the form "Foo;" or "let _ = Foo;" were encountered
where Foo had a destructor, the destructors were not run. This changes
the relevant locations in trans to check for ty::type_needs_drop and invokes
trans_to_lvalue instead of trans_into.

Closes #4734
Closes #6892
rust-mode cleanup.

* Use `setq-local' instead of (set (make-local-variable ...) value).
  Provides a version for older Emacsen.
* Remove use of `cl.el'.
* Use \' in file regexp instead of line end match $.
* Use type for defcustom and add parent group.
Collect move errors before reporting

This commit changes the way move errors are reported when some value is
captured by a PatIdent. First, we collect all of the "cannot move out
of" errors before reporting them, and those errors with the same "move
source" are reported together. If the move is caused by a PatIdent (that
binds by value), we add a note indicating where it is and suggest the
user to put `ref` if they don't want the value to move. This makes the
"cannot move out of" error in match expression nicer (though the extra
note may not feel that helpful in other places :P). For example, with
the following code snippet,

```rust
enum Foo {
    Foo1(~u32, ~u32),
    Foo2(~u32),
    Foo3,
}

fn main() {
    let f = &Foo1(~1u32, ~2u32);
    match *f {
        Foo1(num1, num2) => (),
        Foo2(num) => (),
        Foo3 => ()
    }
}
```

Errors before the change:

```rust
test.rs:10:9: 10:25 error: cannot move out of dereference of `&`-pointer
test.rs:10         Foo1(num1, num2) => (),
                   ^~~~~~~~~~~~~~~~
test.rs:10:9: 10:25 error: cannot move out of dereference of `&`-pointer
test.rs:10         Foo1(num1, num2) => (),
                   ^~~~~~~~~~~~~~~~
test.rs:11:9: 11:18 error: cannot move out of dereference of `&`-pointer
test.rs:11         Foo2(num) => (),
                   ^~~~~~~~~
```

After:

```rust
test.rs:9:11: 9:13 error: cannot move out of dereference of `&`-pointer
test.rs:9     match *f {
                    ^~
test.rs:10:14: 10:18 note: attempting to move value to here (to prevent the move, you can use `ref num1` to capture value by reference)
test.rs:10         Foo1(num1, num2) => (),
                        ^~~~
test.rs:10:20: 10:24 note: and here (use `ref num2`)
test.rs:10         Foo1(num1, num2) => (),
                              ^~~~
test.rs:11:14: 11:17 note: and here (use `ref num`)
test.rs:11         Foo2(num) => (),
                        ^~~
```

Close #8064
Tweaked the design to be a lot cleaner.

Signed-off-by: Daniel Fagnan <dnfagnan@gmail.com>
fixed issues

Signed-off-by: Daniel Fagnan <dnfagnan@gmail.com>
doc: design changes cleanups

Conflicts:
	src/librustdoc/html/layout.rs
Replace 'region' with 'lifetime' in a few transmute function names
Fixes #13507

Fixes hashing of DefId for ty_enum.

Adds tests for cross-crate TypeId equivalence for various types.
rustdoc: add webfonts and tweak the styles accordingly
std: Update documentation on the `comm` module

Some of this documentation got a little out of date. There was no mention of a
`SyncSender`, and the entire "Outside the runtime" section isn't really true any
more (or really all that relevant).

This also updates a few other doc blocks and adds some examples.
libc: Deglob reexports. #11870
optimized SipHash implementation

work started from @gereeter's PR: https://github.com/mozilla/rust/pull/13114
but adjusted bits
Improve the copying code for slices and Vec
auto merge of #13511 : Meyermagic/rust/enum_typeid, r=alexcrichton

Fixes #13507.

I haven't familiarized myself with this part of the rust compiler, so hopefully there are no mistakes (despite the simplicity of the commit). It is also 5am.
Remove usage of private enum variants

This replaces all uses of private enum variants with a struct that has
one private field pointing at a private enum.

RFC: 0006-remove-priv
auto merge of #13498 : johnsoft/rust/fix-transmute-fn-names, r=alexcrichton

Regions were renamed to lifetimes a while back, so these functions should probably be renamed as well.
Make Vec::clone and slice::to_owned failure-safe
Remove RUST_LOG="::help" from the docs

This feature is no longer present in the current version, it was removed along
with the crate map.
dist: Make Windows installer uninstall first. Closes #9563

This will remove existing files before installing new ones. Note
that I took some code with no license from stackoverflow, as
indicated in comments.
Change AUTHORS section in the man pages

The man pages no longer contain Graydon Hoare as the project lead.

Fix #13509.