Allow setting arrays of arrays as searchoption

**The Issue:**
Currently there is no way to set an ordered list of elements as searchoptions for searchtype select.

**Justification for this PR:**
Currently there are two(three) different ways to set the elements as searchoptions.
* String, has delimiters and is inefficient for large lists.
* Object, ordering is browser (version) dependent, newer browsers sort the objects elements by key, which makes it almost impossible to sort them by value and still keep the entries id/key usefull.
* External, lot of overhead especially for small lists

**PR Breakdown:**
This PR allows the user of jqGrid to provide their searchoptions values as array of arrays.
````javascript
{name:'AnswersToQuestion42', index:'columnq42', width:60, search:true, stype:'select', searchoptions:{value: [[1,"Truth"], [2, "Power"], [3, "Relyability"]] } },
````