Update the linenoise library
Set the USE_UTF8 flag for linenoise to handle utf8-input
Fix compilation errors with linenoise
auto merge of #6728 : alexcrichton/rust/update-linenoise, r=Aatch

This updates the bundled linenoise library, and explicitly builds it with UTF8 support. This way rusti correctly handles utf8 characters when doing line operations.

Closes #6681