[dev] combine severay Horde_Rdo_Query objects

[Sebastian Birnbach]

I whish to perform a search of the shape

(A AND B) OR (A AND C) ORDER BY D

I see that one Horde_Rdo_Query object will permit only one conjunction AND
or OR. If I use two distinct queries I will have to implement the sorting
myself.

So, is there a way to combine several query objects to the purpose? Or any
other way to use a more complex search expression?