Use grep ignoring alias

Many people out there use an aliased grep. Eg aliased to [ag](https://github.com/ggreer/the_silver_searcher) or [ack](https://github.com/petdance/ack2). The aliased grep may not have a -q option, so to improve compatibility i suggest that the unaliased grep is used instead.
Merge pull request #4 from Zorbash/master

Use grep ignoring alias