VideoConfig/LocalConfig/HotkeyManager: Added hotkeys for switching stereo-3d presets.

Added 3 depth/convergence presets. They are adjustable via (existing) hotkeys - changes to depth and convergence are applied to current preset.
Added 3 hotkeys for activating presets. Added hotkey for toggle between first and second preset.
Added OSD message for convergence/depth changes.
Presets are saved into per-game configs.

Source/Core/Core/HotkeyManager.cpp

@@ -116,6 +116,12 @@ const std::string hotkey_labels[] =
 	_trans("Undo Save State"),
 	_trans("Save State"),
 	_trans("Load State"),
+
+	_trans("Toggle 3D Preset"),
+	_trans("Use 3D Preset 1"),
+	_trans("Use 3D Preset 2"),
+	_trans("Use 3D Preset 3"),
+
 };
 static_assert(NUM_HOTKEYS == sizeof(hotkey_labels) / sizeof(hotkey_labels[0]), "Wrong count of hotkey_labels");
 

Source/Core/Core/HotkeyManager.h

@@ -117,6 +117,11 @@ enum Hotkey
 	HK_SAVE_STATE_FILE,
 	HK_LOAD_STATE_FILE,
 
+	HK_SWITCH_STEREOSCOPY_PRESET,
+	HK_USE_STEREOSCOPY_PRESET_0,
+	HK_USE_STEREOSCOPY_PRESET_1,
+	HK_USE_STEREOSCOPY_PRESET_2,
+
 	NUM_HOTKEYS,
 };