New command to save query results into a file

[rantolin]

In order to save query results to a file, it is possible to pipe them to a file. And once issue #3 is ready, we will be able to store them in different format.

However there are two different caveats about this:

1. It won't be possible to store binary formats.
2. To reduce data traffic, query results will limited (see issue Query results must be limited #5).

We need a way to store ALL results from a query into a file in both text and binary formats.