Added variable for restart program parameters

I have a plugin which is expected that only one instance of gVim is running. And restart.vim plugin does not work correctly.
At first time I used g:restart_vim_progname to pass necessary parameters to gVim program but they were shellescaped into one big string that is not runnable (shell always returns "program not found").
And then I introduced special List for the progname which allows me to restart vim without my special module.
I think I'm not alone with this issue. My example is only one of many. But your plugin is incredible, I always dream about such opportunity to restart vim in any time! And I will be appreciated if you merge my changes into upstream.

Thanks,
Igor.