Even more search improvements

So...
- I moved search button to the top, 
- added bigger and more obvious More button, 
- did some cleaning (removed unused code and template) and... 
- :boom: replaced search POST request with GET request, so that search url gets updated and can be bookmarked. :smirk_cat: 

Also, I replaced _search_ parameter with _q_, so it is consistent with clickable searchable tags.

:cop: Code review anyone? @ercchy maybe? @goranche? @gandalfar?