add persistent query and paging

[crsct]

closes #45 by adding the base64 encoded query to the url

[lukasjelonek]

I observed the following changes:

• The search is executed everytime, even on the first page load. Previously it was required that the user presses the search button
• Everytime the page is reloaded, two search requests are send to the server
• When the second page is opened and the page is reloaded, it loads the first page
• When the second page is opened and the back button is used, the second page is reloaded

The network traffic suggests that one of the two requests requests the current page and the other requests the expected page. Getting rid of the first one should eliminate most of the problems stated above.