Highlights:
* Adds an 'uninstall.sh' script to `/usr/local/lib/rustlib/uninstall.sh`, the path to which is printed during installation.
* Components can be deselected during install, like `install.sh --without=rust-docs`.
* Components can be listed with `install.sh --list-components`.
* Vastly reduces spew during install (but supporting a `--verbose` option).
Typicall install run looks like:
```
brian@brianX1:~/dev/multirust⟫ sudo ./install.sh
[sudo] password for brian:
install: creating uninstall script at /usr/local/lib/rustlib/uninstall.sh
install: installing component 'rustc'
install: installing component 'cargo'
install: installing component 'rust-docs'
Rust is ready to roll.
```
Needs to be merged right before corresponding PRs to cargo and rust-packaging.
Fixes https://github.com/rust-lang/rust/issues/21117
Fixes https://github.com/rust-lang/rust/issues/20283
Added all active features to the list in reference.md.
Added a second note about keeping the reference.md list up-to-date to the bottom of the list, since not everyone (including me) reads the big comment at the top of it. :)
Ensured that the feature gate list in reference.md is kept in alphabetical order.
While having a look at the Rust book I found this tiny error. In my opinion this if should be all lowercase, because it follows a colon, but I am no native speaker, so I am probably wrong. Also it is a very tiny change, so feel free to include it in any bigger documentation patch.
Removes the link to the rust-dev mailing list in the bug report submission page and also adds the address of the IRC server (`irc.mozilla.org`). Addresses #22249.
Added a second note about keeping the reference.md list up-to-date to
the bottom of the list, since not everyone (including me) reads the
big comment at the top of it. :)
Ensured that the feature gate list in reference.md is kept in
alphabetical order.
Replaced outdated use of the `range(start, end)` function where
approriate with `start..end`, and tweaked the examples to compile and run with the latest rust. I also fixed two periphery compile issues in reference.md which were occluding whether there were any new errors created by these changes, so I fixed them.
I started to write up some docs on this, and then realized I was just repeating http://huonw.github.io/blog/2015/01/peeking-inside-trait-objects/ but worse. @huonw previously said that we can use this content if we wanted, so I made some tweaks and integrated it into the book.
Fixes#21707
