message: Modified the help information of cargo-rustc
diff: @@ -5,9 +5,9 @@ use cargo::ops;
  pub fn cli() -> App {
  subcommand("rustc")
  .setting(AppSettings::TrailingVarArg)
  - .about("Compile a package and all of its dependencies")
  + .about("Compile a package, and pass extra options to the compiler")
  .arg(opt("quiet", "No output printed to stdout").short("q"))
  - .arg(Arg::with_name("args").multiple(true))
  + .arg(Arg::with_name("args").multiple(true).help("Rustc flags"))
  .arg_package("Package to build")
  .arg_jobs()
  .arg_targets_all(
  