Add platform detection install script similar to 'rustup.sh'

[bvssvni]

• Should use target triple instead of just linux, win and mac.
• Support both install and uninstall

Source:

http://www.rust-lang.org/rustup.sh

Link suggestion:

http://www.rust-lang.org/cargoup.sh

[wycats]

👍

@alexcrichton what do we have to do to make this happen. We also discussed last week having it included in the Rust rustup.sh and @brson seemed amenable to the idea iirc.

[steveklabnik]

Super +1 to just having it in the Rust rustup.sh, because then you'll
never get a version mismatch.

[brson]

Cargo still needs a strategy for installing and uninstalling itself. rustup is just a script that downloads and runs an installer.

I might suggest having it 'tap into' Rust's installer so, register itself in the manifest, so that the Rust installer also uninstalls cargo, but Rust has multiple installation methods, not all of which use the same uninstall mechanism.

[alexcrichton]

cc rust-lang/prev.rust-lang.org#46

[alexcrichton]

Merged upstream!

The main rustup.sh script now installs cargo unless you specify --disable-cargo

[bvssvni]

Nice!