- current search context is saved when the plugin saves its state (only the tags search for now - the fulltext search will come later).
- add an area displaying the current preset name in a more visible way - since otherwise, there was no way to know what the current preset was after loading a saved state
plus some new GUI changes:
- adds new buttons for next/previous presets.
- add parameters to customize the scrollbars width in the skin file.

