Remove jquery dependency in favor of component/dom component.

* Replace `component/jquery` for `component/dom` as dependency.
* Replace `o()` for `dom()` in index.js
* Fixed bugs from differences between jQuery and dom APIs.

`build.js` file size is bigger than before (`~311kb` vs `~287`) because `component/pager` still depends on jQuery. But when pager removes jQuery as dependency, `build.js` should reduce to `~41kb` which is quite an improve.