[FEATURE][REFACTOR] store + models + sort-order + query params improved

**I kept the original text, but this has been updated like crazily thanks to the advices of @stefanpenner so better you go read after [there](https://github.com/gcollazo/ember-cli-addon-search/pull/16#issuecomment-60515270)**

* Each package is now using an `ObjectProxy` with aliases and useful properties
* The search filter is debounced very 100ms
* The search is simply hiding `tr` by css classes which is much faster and does not need re-generating each row
* You can now order by clicking on each column, default sort order being the package name