Move to stable

[skade]

This introduces multiple changes to make exa work on Rust 1.4.0. Detailed reasoning behind all patches:

• 679b9e1: The one instance of sum can be trivially replaced by fold(0, Add::add), dropping a convenience feature flag.
• b3e3825: fs_modes tracking issue currently gives no hope for fs_mode to remain as it is or to be stabilized anytime soon. As the only thing imported is a constant table, this can be copied over into the library - it will most likely break in the future anyways.
• e8ea96e: The RFC for CString convenience conversions has failed and the corresponding methods are flagged for deprecation. Take the route over String instead, which avoids many of the issues described in the corresponding RFC discussion.
• 7f53da7: As the "last" element of the Slice is dropped anyways, this can be expressed using the slicing syntax just as well, dropping the need for a feature that only becomes available in Rust 1.5. Add tests to ensure that the API still holds.
• 7a97b7d: I'm a bit unsure here: I assume that the vector only grows, which allows to use reserve instead of resize, to my reading. Resize will become available in Rust 1.5.

[skade]

Yes. For some reason, 1.3.0 throws this:

   Compiling exa v0.4.0 (file:///Users/skade/Code/rust/exa)
src/output/details.rs:234:17: 280:19 error: invocation of unsafe method requires unsafe function or block [E0133]
src/output/details.rs:234                 scoped.execute(move || {
src/output/details.rs:235                     let mut errors = Vec::new();
src/output/details.rs:236
src/output/details.rs:237                     let mut xattrs = Vec::new();
src/output/details.rs:238                     match file.path.attributes() {
src/output/details.rs:239                         Ok(xs) => {
                          ...
note: in expansion of for loop expansion
src/output/details.rs:229:13: 281:14 note: expansion site
note: in expansion of closure expansion
src/output/details.rs:225:21: 282:10 note: expansion site
src/output/details.rs:234:17: 280:19 help: run `rustc --explain E0133` to see a detailed explanation
error: aborting due to previous error
Could not compile `exa`.

[ogham]

1.3.0 fails because the scoped_threadpool crate makes that particular method unsafe for that version to work around a bug in rustc that’s since been fixed. More details here: #84 (comment)

[skade]

I fixed the tree output by reimplementing resize in terms of a reallocation and a extend.

It's certainly not as efficient as the original, but it works. I added a TODO to keep track that this should be cleaned up after the 1.5.0 release.

[skade]

Moved the constants to a private module.

[ogham]

LGTM! 👍

I’m OK with copy-and-pasting code from libstd in lieu of waiting for some of the features to stabilise, especially if these features are already going to be stabilised soon. The benefit of having everyone able to compile exa themselves outweighs the small cost of ever fixing it if we need to. So thanks very much for this.