Add support for an array of values on DoctrineQueryFilter::addDefaultFilter

I often have the need to use multiple-select box on filters.. for instance to select multiple weeks of the year.
Despite that the value on the DB is an integer when listing and filtering, being able to select multiple weeks is quite handy.
I believe this can be useful on other scenarios as well.

PS- I've worked on branch v1.0 but made the pull request over master. If you accept this change, will you also merge it to branches v1.0 and v1.1?
@loostro I've notice that you've started working on improving filters for v2.0, still I hope you kindly analyse this change.