This functions searches for objects either by executing a key or/and full
text query. The found objects can further be filtered by an optional
object query. They are sorted by their importance. The second search
operation is relatively slow and its result can be limited to a certain
number of hits. This allows to perform an incremental search, each
returning just a subset of all found documents, starting at a given
index. The parameter array contains the 'keyquery' or/and 'fulltextquery'
depending on who you would like to search. Optional parameters are
'objectquery', 'scope', 'languages' and 'attributeselector'. In case of
an incremental search the optional parameters 'startIndex',
numberOfObjectsToGet' and 'exactMatchUnit' can be passed.