Clean up the GUI and improve the usability

With more and more functions integrated in the GUI we need to change the visibility and arrangement of the items. Because of space reasons it is not possible to put more and more tabs into the left accordion (with the corpus list and the search options). Instead all additional functions like export and (the currently not finally implemented) frequency analysis become part of the main tab bar and can be triggered by a "more" button next to the search button.

![annis_guilifting_empty](https://f.cloud.github.com/assets/2168104/1165262/b1b7aec4-2069-11e3-8ee7-87936ccdee4d.png)

In order not to clutter the main tab bar all tabs (except the "Help") can now be closed. There are also some visual guidances like icons to help the user to find the right tab.

![annis_guilifting_queryresult](https://f.cloud.github.com/assets/2168104/1165266/b516387e-2069-11e3-88bb-0a45f29d5328.png)
![annis_guilifting_export](https://f.cloud.github.com/assets/2168104/1165264/b4f205da-2069-11e3-9fda-2ae39b82ad6f.png)

The query builder still belongs to the main tab, but is not visible by default. Instead a huge button with icon next to the search text field (instead of the "AnnisQL" label) triggeres the query builder.

The query builder itself was also enhanced, the buttons now have additional text and are clearly marked as clickable buttons.

![annis_guilifting_query_builder](https://f.cloud.github.com/assets/2168104/1165265/b502dbe4-2069-11e3-96c4-ea69b01433f1.png)