Fix spacing issue in clientutils
* Make fillForm part of the Casper prototype
* Remove casper parameter from fillForm, and update code to use 'this' instead
* Add names to selectorFunction functions to improve stack trace clarity
* Remove 'self' parameter from selectorFunctions
* Use 'call' to set the correct value for 'this' when invoking selectorFunctions
Made parameter names more specific in selectorFunction functions