search work using django templates

Please review this a bit before eventually pull it.
this pr works mainly on the search page and search engine:
- django based(shared) templates snippets for items
- full server side search and filter
- multiple type seach
- server side category search
- pagination of the results
- new search page layout (attached image)
- fix rating on paginated results

If we like this I will go on and use part of the templates also in home page(latest layers), map explore, layer explore, document explore, people explore.

(sorting is still broken, will work on it)

Thanks for any comments and suggestion!

![Screen Shot 2013-02-13 at 16 50 23](https://f.cloud.github.com/assets/779380/153366/1dcbbf94-75f5-11e2-8dfd-3bae904563bf.png)