libc bindings for glob.h

only tested on linux/x86_64, but i got the values for other platforms
from their system header files.

no bindings for win32, because win32 doesn't include glob.h.

also, glob() takes a callback for error handling, but i'm just making
this a *c_void for now, since i don't know how to represent c calling
back into rust (if that's even currently possible).
add a higher level glob() function to os

this could probably use expansion - it just uses all of the default
options, which is usually what we want, but not always. maybe add a
separate function that takes more options?
libcore: add N(0,1) and Exp(1) distributions to core::rand.

Sample from the normal and exponential distributions using the Ziggurat
algorithm.
glob_t should be public on all platforms
Revert rename of Div to Quot
auto merge of #6147 : bjz/rust/numeric-traits, r=brson

After much discussion on IRC and #4819, we have decided to revert to the old naming of the `/` operator. This does not change its behavior. In making this change, we also have had to rename some of the methods in the `Integer` trait. Here is a list of the methods that have changed:

- `Quot::quot` -> `Div::div`
- `Rem::rem` - stays the same
- `Integer::quot_rem` -> `Integer::div_rem`
- `Integer::div` -> `Integer::div_floor`
- `Integer::modulo` -> `Integer::mod_floor`
- `Integer::div_mod` -> `Integer::div_mod_floor`
core: Remove use of deprecated `drop`
syntax: remove parsing destructors
rustc: remove the rest of drop

Removes:

ast::struct_def::dtor
syntax::ast::ii_dtor
syntax::visit::fk_dtor
syntax::ast_map::node_dtor
syntax:struct_dtor
allow parsing attributes on struct fields
syntax: remove parse::token::{dtor,literally_dtor}
remove some warnings
rustdoc: Remove a now invalid test
pipes: use finally to fix pipes::try_recv
auto merge of #6148 : erickt/rust/remove-drop, r=pcwalton

The drop block has been deprecated for quite some time. This patch series removes support for parsing it and all the related machinery that made drop work.

As a side feature of all this, I also added the ability to annote fields in structs. This allows comments to be properly associated with an individual field. However, I didn't update `rustdoc` to integrate these comment blocks into the documentation it generates.
auto merge of #5832 : doy/rust/glob, r=graydon

This adds low level bindings for `glob()` and `globfree()` in `libc`, and adds a static `glob()` function to `Path` which uses those. It has only been tested on Linux/x86_64, but I looked up header file definitions for other platforms, so they should hopefully work in theory. Windows doesn't have these functions, so that is currently unimplemented, although ideally `Path::glob()` could be reimplemented in terms of Windows primitives instead, at some point in the future.

I'm not sure what a good way to test this would be - it requires looking at the actual filesystem, so I'm not sure where a safe place to do that would be. I'd be willing to add some if people have recommendations.
auto merge of #6098 : huonw/rust/core-rand-dists, r=graydon

(This is only a94c86e, the other two are from #6073.)

Very basic support for sampling from N(0,1) and Exp(1). This is basically my experimentations with the Ziggurat algorithm, and will certainly get reorganised when [Lib-rand](https://github.com/mozilla/rust/wiki/Lib-rand) gets finished.

No tests or anything, other than generating 1 million numbers from each distribution, loading it into R and plotting and performing some basic tests (which passed) i.e. Pearson's chi-squared for the Exp(1) values, and Shapiro-Wilks for the N(0,1) values.

![normal-exp](https://f.cloud.github.com/assets/1203825/435879/097fbf4e-b011-11e2-90fe-6cf9a7f80dce.png)

(These will be tested better when the lib rand changes linked above start to happen.)

(Also, it's not hugely relevant, but I noticed that this is about double the speed of R for summing 10000000 samples from the normal distribution, even though the current random-float code is subobtimal.)

No need to merge this if it seems like it's being too hasty.
MINOR: Comment ty::TraitStore and ty::vstore
Add trait object field types to back/abi.rs, and use them

I've added trt_field_vtable, trt_field_box, and trt_field_tydesc, and
inserted them in place of the "magic numbers" used to access trait
object fields through GEPi().