search for more than one word / #5164

Currently searching for multiple words uses OR relation, which is of course useless. The problem here is that mysql either provides a loose search ("bla" matching "blasphemy") or an AND search ("bla" not matching "blasphemy").

There are severaly ways to fix this:

1. Several words always use tight mode (not very good because you will miss a lot of results)
2. Several words use loose mode for mysql and php for filtering AND wise afterwards (not very performant)
3. Some way of advanced syntax like:
   • "bla AND pop"
   • "bla OR pop"
   • "bla* OR pop*"
   • "bla* AND pop*"

I am not sure, whether the wildcard thing is too overdone.

Also filtering search results for different types and status would also be a nice feature.