add rustdoc comments with examples for the string versions of to_base64 and from_base64
rustpkg: Factor out tests; use a condition instead of returning an option

Pulled out tests into their own modules inside the files they test,
as per the draft style guidelines.

Started a new module, path_util, for utility functions to do with
paths and directories.

Changed default_dest_dir to use a condition and return Path
instead of Option<Path>.
Add comments for the implementations of from_base64 and to_base64 for .
move rustdoc comments so that they attach to the functions rather than the impl blocks.
Doc review, as requested :-).

Mostly just phrasing things differently, which is a matter of taste. Feel free to use or not use any of the changes I'm suggesting.

I would say this one thing should be changed, though, not necessarily the way I changed it here.

     * Convert any string (literal, `@`, `&`, `~`)
     * that contains a base64 encoded value, to the byte values it encodes.

If this structure is going to be used, either the entire clause, 'that contains a base64 encoded value', should be bracketed by commas, or the comma at the end of the clause should be removed.
Merge pull request #1 from danluu/silly_style_changes

Doc review, as requested :-).
Add a lint mode for unused unsafe blocks/functions
core: remove unnecessary unsafe blocks/functions
std: remove unused unsafe blocks/functions
rustc: remove unnecessary unsafe blocks/methods
syntax: remove unnecessary unsafe blocks/functions
test: remove unnecessary unsafe blocks/functions
update copyright notice on base64.rs
Change to 4-space indents in code examples
Tidy
auto merge of #5797 : alexcrichton/rust/issue-1913, r=catamorphism

Closes #5487, #1913, and #4568

I tracked this by adding all used unsafe blocks/functions to a set on the `tcx` passed around, and then when the lint pass comes around if an unsafe block/function isn't listed in that set, it's unused.

I also removed everything from the compiler that was unused, and up to stage2 is now compiling without any known unused unsafe blocks.

I chose `unused_unsafe` as the name of the lint attribute, but there may be a better name...
auto merge of #5891 : brson/rust/valgrind, r=brson

Hopefully this puts out the final fire
auto merge of #5861 : catamorphism/rust/rustpkg, r=catamorphism

r? @graydon

Pulled out tests into their own modules inside the files they test,
as per the draft style guidelines.

Started a new module, path_util, for utility functions to do with
paths and directories.

Changed default_dest_dir to use a condition and return Path
instead of Option<Path>.
auto merge of #5879 : astrieanna/rust/document_std_base64, r=catamorphism

This adds examples for the methods in std::base64.

Each example is complete in the sense that you can copy-paste it into a file and compile it successfully without adding anything (imports, etc). The hardest part of figuring out how to use this was figuring out the right import statements to put at the top.
Update AUTHORS.txt w/ Brett Cannon, Diggory Hardy, Jack Moffitt, James Miller