* Joystick hotplug support (#4141)
* use SDL_PollEvent instead of SDL_JoystickUpdate
Register hot plugged controller by GUID if they were configured in a previous session
* Move SDL_PollEvent into its own thread
* Don't store SDLJoystick pointer in Input Device; Get pointer on each GetStatus call
* Fix that joystick_list gets cleared after SDL_Quit
* Add VirtualJoystick for InputDevices thats never nullptr
* fixup! Add VirtualJoystick for InputDevices thats never nullptr
* fixup! fixup! Add VirtualJoystick for InputDevices thats never nullptr
* Remove SDL_GameController, make SDL_Joystick* unique_ptr
* fixup! Remove SDL_GameController, make SDL_Joystick* unique_ptr
* Adressed feedback; fixed handling of same guid reconnects
* fixup! Adressed feedback; fixed handling of same guid reconnects
* merge the two joystick_lists into one
* make SDLJoystick a member of VirtualJoystick
* fixup! make SDLJoystick a member of VirtualJoystick
* fixup! make SDLJoystick a member of VirtualJoystick
* fixup! fixup! make SDLJoystick a member of VirtualJoystick
* SDLJoystick: Addressed review comments
* Address one missed review comment
Instead, we make a proper registry class and house it within the main
window, then pass it to whatever needs access to the loaded hotkeys.
This way, we avoid a global variable, and don't need to initialize a
std::map instance before the program can do anything.
Instead of using an unsigned int as a parameter and expecting a user to
always pass in the correct values, we can just convert the enum into an
enum class and use that type as the parameter type instead, which makes
the interface more type safe.
We also get rid of the bookkeeping "NUM_" element in the enum by just
using an unordered map. This function is generally low-frequency in
terms of calls (and I'd hope so, considering otherwise would mean we're
slamming the disk with IO all the time) so I'd consider this acceptable
in this case.
