use "pacman -Sl" instead of "pacman -Ss <pkgname>"

~~~
pacman_package 'bind' do
  action :upgrade
end
~~~

This does not work because `pacman -Ss bind` contains the following.

~~~
extra/gkeyfile-sharp 0.1-3
    Mono bindings for GLib\xE2\x80\x99s GKeyFile
~~~

Because of this, `/^(#{package_repos})\/#{Regexp.escape(@new_resource.package_name)} (.+)$/` fails with the following error.

~~~
ArgumentError: invalid byte sequence in US-ASCII
~~~

So, I suggest using `pacman -Sl` instead of `pacman -Ss <pkgname>`. `pacman -Sl` does not output description of packages.