Switch ComputeHash64 len param to size_t instead of int

Updated nihstro to latest master. Fix warning on MSVC

fixed the override warning

```
In file included from citra/src/audio_core/sink_details.cpp:11:
citra/src/./audio_core/sdl2_sink.h:25:10: warning: 'SetDevice' overrides a member function but is not marked 'override' [-Winconsistent-missing-override]
    void SetDevice(int device_id);
         ^
citra/src/./audio_core/sink.h:39:18: note: overridden virtual function is here
    virtual void SetDevice(int device_id) = 0;
                 ^
```

More shader refactoring

* Initial Commit

Added Device logic to Sinks
Started on UI for selecting devices

Removed redundant import

* Audio Core: Complete Device Switching

Complete the device switching implementation by allowing the output
device to be loaded, changed and saved through the configurations menu.

Worked with the Sink abstraction and tuned the "Device Selection"
configuration so that the Device List is automatically populated when
the Sink is changed.
This hopefully addresses the concerns and recommendations mentioned in
the comments of the PR.

* Clean original implementation.

* Refactor GetSinkDetails

This doesn't belong in LoadInputVertex because it also happens for
non-VS invocations. Since it's not used by the JIT it seems adequate to
initialize it in the interpreter which is the only thing that cares
about them.

Currently there's only a single dummy implementation, which will be
split in a following commit.

This removes all implicit dependency of ShaderState on global PICA
state.

Service/NFC: stub some functions

Fixing some MSVC warnings

Changed the FAQ link so it leads to the FAQ on the Citra website, instead of the FAQ hosted
on GitHub

Removed unused and outdated external qhexedit

HID: reset acceleroeter and gyroscope index in Init

Updated Citra forum link

The Citra forum (discuss.citra-emu.org) has recently been down. The link that has been added 
in this file now leads to an error pages. I update updated the link so it now leads to Citra's new
forum.