Hotkeys in dialogs. Step 2. Reacting to the keys

Push/Radio/Check buttons now react to their hot keys.
The functionality is successfully tested on Win and on Linux.

Remaining stuff:
- Change hotkey color to red in dialogs, while keeping it yellow in menus. Can this be done by adding colors to colors-style.cpp? If so, could guidelines on adding colors be added to the file?
- Add hotkeys to other dialog elements (text inputs, anything else?)
- Markup dialogs with hotkeys