Typeck: Disallow scalar casts to bare_fn.

Bare functions are another example of a scalar but non-numeric
type (like char) that should be handled separately in casts.
This disallows expressions like `0 as extern "Rust" fn() -> int;`.

It might be advantageous to allow casts between bare functions
and raw pointers in unsafe code in the future, to pass function
pointers between Rust and C.

Closes #8728
doc: switch pandoc to html5
doc/rust.HTML: proper version box
Fix unicode errors on Windows in path_is_dir, path_exists, getcwd and rust_localtime.

This make these functions use wchar_t version of APIs, instead of char version.
testsuite: test for fixed issue. Closes #7580.

Fixed by the privacy changes that allowed the `mod std {}` at the top
level of `std` to be non-`pub`.
auto merge of #9973 : huonw/rust/7580, r=luqmana

Fixed by the privacy changes that allowed the `mod std {}` at the top
level of `std` to be non-`pub`.
auto merge of #9812 : HNO3/rust/windows-utf8, r=alexcrichton

This fixes #9418 and #9618, and potential problems related to directory walking.
fix typo
Don't allocate a string when calling println

Instead use format_args! to pass around a struct to pass along into std::fmt
Use updated local declaration syntax.
doc: tidy and cleanup CSS deps, add tutorial PDF generation
doc: expand tutorial/manual CSS

Cleanup, edit, add some Bootstrap v3.0.0 elements.
rustdoc: nitpicks & cleanup
doc: fix links to comply with the new rustdoc

Closes #9911.
auto merge of #9976 : thestinger/rust/typo, r=thestinger
expose new floating point intrinsics

copysign, ring, nearbyint, round
auto merge of #9979 : alexcrichton/rust/print-no-alloc, r=huonw

Instead use format_args! to pass around a struct to pass along into std::fmt
Add a feature flag for ASM
auto merge of #9991 : LeoTestard/rust/asm-feature-gate, r=huonw

Fixes #9882
Note that the actual checking code is inside a if false in order to compile libstd properly.
libstd uses asm! in rt. If we put ```#[feature(asm)]``` in libstd, it fails to build at stage0 beacause the
asm feature is not known yet by the snapshot compiler.
We must wait that this PR arrives into the snapshot in order to actually activate the checking code.
Make fn pub for windows compatibility