v4.2.0 Pre-Release 1: USB fixes and Riffmaster joystick support!

Yes I skipped the full release for v4.1.0, didn't realize until making this release lol

Additions

• A new status label has been added above the Start button to explain why the Start button may be disabled, guiding you in what steps need to be taken to get it enabled.
• The Riffmaster now has special handling in ViGEmBus mode to map its joystick to the left stick on Xbox 360 controllers.
  • This mapping does not happen in vJoy mode, as the current setup for vJoy does not have enough axes configured to allow mapping the stick, and changing it would necessitate re-configuring and rebinding controls, which I don't feel like making people do. If this mapping is desired, let me know and I'll consider changing this.
  • The mapping also does not apply to RPCS3 compatibility mode, as there is no equivalent on a PS3 Rock Band guitar that it could be mapped to. If this mapping is desired, let me know.

Changes

• Neither the Pcap nor USB backends are enabled by default anymore, you must enable one or the other.
• The Configure Devices button has been renamed to Configure USB Devices to help clarify what its purpose is.
• ViGEmBus mode no longer uses a hardware-accurate mapping, and instead maps drums and cymbals fully separately.
  • You will need to remap your controls after this change! Also, if you have a second kick pedal, you will not be able to map it in Clone Hero v1.0.0.4080-final without doing the workaround for mapping axis inputs. This is a concession that had to be made to allow cymbals to be mapped fully individually.
• USB devices are now restarted when hitting Start or Stop, to ensure proper initialization and function of devices.
  • This comes with a message in the console to indicate what is going on, along with a note to reconnect the device if the process takes longer than 15 seconds or so. (It should realistically take less than 5 seconds.)

Fixes

• The Configure USB Devices button is now disabled when hitting the Start button.
• An issue with the initialization sequence of USB devices has been fixed (tl;dr there was a 1 in 254 chance that a device would actually initialize properly, depending on when it was plugged in).
• Controller emulation mode changes now apply correctly to USB devices, and no longer require a restart to take effect.