Set device category for MIDI controllers.
Fix some usability issues in the controller preferences page. Bug #1304964

* Use a tab widget instead of a toolbox.
* Move troubleshooting link to the support link list.
* Move MIDI learn button to controller info header.
* Add more edit triggers to the input/output mapping tables.
Vinyl seek should always be seekExact
Avoid hammering ->get() calls in wspinny.
Remove unnecessary check
Merge pull request #231 from ywwg/spinny-avoid-gets

Avoid hammering ->get() calls in wspinny.
Add a reset to defaults button to the Preferences chrome.

* Remove all individual page reset buttons.
* Add reset logic to Library page.
* Add TODOs to write reset logic for interface, modplug, recording, shoutcast
  and vinyl control pages.
Add preset author explicitly to preset info tab.

Ideally we should make these editable so that a user could create a mapping in
the GUI and then hit the Export button to save it.
Switch to traditional key notation as default.
Select and scroll to new mapping row when adding. Fixes Bug #1308204.
Disable learnign wizard button if controller is not mappable.
Move controller info into a Controller Setup tab. Bug #1304964.
Don't disable the setup tab if the device is not open.
DN-MC6000MK2: Initial revision
DN-MC6000MK2: Map some controls and the VU meter LEDs directly
DN-MC6000MK2: Looping

- Loops: Manual, beat and beatroll
- Censor: Use reverseroll instead of reverse
- Scratching: Don't modify keylock mode