Fix for TS 0.9.1

Removed extra overload of ensureSelectElementIsRenderedCorrectly to
prevent this compiler error with TS 0.9.1: "error TS2175: Overloads
cannot differ only by return type.".  Also amended jasmine switching
bool to boolean so tests pass.

knockout/knockout.d.ts

@@ -298,8 +298,6 @@ interface KnockoutUtils {
 
     setElementName(element: any, name: string): void;
 
-    ensureSelectElementIsRenderedCorrectly(selectElement);
-
     forceRefresh(node: any): void;
 
     ensureSelectElementIsRenderedCorrectly(selectElement: any): void;