Support for inline-block/floated elements

- it's for issue <a href="https://github.com/angular-ui/ui-utils/pull/234">#234</a> of ui-utils (Support for inline-block/floated elements in ng-scroll)

- conversion <a href="https://github.com/david-hollifield">david</a>'s code to cofee, checking, refactoring

- pre-rendered elements hiding feature