rust maker parameter causes wrong error report

[zekzekus]

when i open my rust source files with neovim, neomake usually have an error on first line if there is an extern crate statement.

i checked sytastic plugins syntax_checker for rust programs and it uses -Z parse-only and does not raise warning for the extern crate lines.

neomake rust makes does not use this parse-only argument but using -Z no-trans. when i checked descriptions for these params:

    -Z                   parse-only -- parse only; do not compile, assemble, or link
    -Z                     no-trans -- run all passes except translation; no output

i think to use parse-only for rust make is a better idea.

[zekzekus]

please check #276

[jonhoo]

A better long-term solution would probably be to use the rust.vim syntax checker definition like syntastic does. That way, we don't have to maintain on of our own.