document what unsafety means

Closes #9144
Ignore a test which is blocking a snapshot

@catamorphism says he has a fix coming soon, so I didn't allocate an issue for
it. If it festers for more than a few days I'll open something up though.
auto merge of #9269 : alexcrichton/rust/ignore-rustpkg-test, r=brson

@catamorphism says he has a fix coming soon, so I didn't allocate an issue for
it. If it festers for more than a few days I'll open something up though.
Generate random big integers within a range

Thanks to @huonw for feedback
auto merge of #9258 : thestinger/rust/doc, r=catamorphism

Closes #9144
auto merge of #9133 : dcrewi/rust/bigint-random-range, r=huonw
Added support for a `\0` escape sequence.

This commit adds support for `\0` escapes in character and string literals.

Since `\0` is equivalent to `\x00`, this is a direct translation to the latter
escape sequence. Future builds will be able to compile using `\0` directly.

Also updated the grammar specification and added a test for NUL characters.
std: Fix an invalid read in from_c_multistring

When `count` is `Some` this function was reading a byte past the end
of the buffer.
auto merge of #9281 : brson/rust/multistring, r=alexcrichton

When `count` is `Some` this function was reading a byte past the end
of the buffer.
auto merge of #9248 : DanRosenwasser/rust/master, r=alexcrichton

Since `
Methodyfied extra::getopts