Also cleanup selection state on initialization - for cases where an application has selection/focused/anchor on items which do not exist anymore
Directly call ko.utils.arrayForEach instead, as observableArray().forEach breaks in IE8
Make use of ko.utils.arrayIndexOf and ko.utils.arrayForEach explicit rather
 than depend on the Array.prototype versions (for old browser compatibility)
Add old browser compatibility for event.target, for when jQuery is not included
Merge pull request #45 from mwoc/master

Validate selection/focused/anchor during initialization