return php array if field is multivalued
check if is not an array instead of is_string. Could be int value
Merge pull request #30 from Domisys/fix-multivalued-fields

Fix multivalued fields
the second occurence is now correctly filed in returned array
Merge pull request #31 from Domisys/fix-multivalued-fields-second-occurence-is-not-filed

Multivalued fields - Second occurence was not here
Fix #32. Sort supports simple string or array as parameter.
Implements #34