Edited Issue: Multi-Select Dropdown Controls Don't Have Name Attributes [10206]

In SP2007 and 2010, I'm finding the different bits of multi-select dropdowns using selectors like this:
``` javascript
// Find the important bits of the multi-select
if(childSelect.Type === "M") {
MultiLookupPickerdata = childSelect.Obj.closest("span").find("input[name$='MultiLookupPicker$data']");
master = window[childSelect.Obj.closest("tr").find("button[id$='AddButton']").attr("id").replace(/AddButton/,'MultiLookupPicker_m')];
currentSelection = childSelect.Obj.closest("span").find("select[ID$='SelectResult']");
}

```
In SP2013, there is no name attribute, so these selectors are failing.

I'm taking this opportunity to move more of the selector logic into the DropdownCtl constructor.

This issue affects:
* SPCascadeDropdowns
* SPFilterDropdown
* SPSetMultiSelectSizes