Make hoodie install and hoodie new windows compatible

`hoodie new` and `hoodie install` finally work on Windows. As said (https://github.com/hoodiehq/hoodie-cli/pull/87#issuecomment-34765050) the npm binary path contained a space and missed the .cmd ending what resulted in an ENOENT.
Also on Windows machines `cp` is unavailable and mkdir has no option `-p` (it simply creates a directory `-p`, silly windows :).