videocore: Added RG8 texture support

Update boost external to v1.59.0

Fix Linux GCC 4.9 build (complaining about undeclared memset)

citra-qt: Improve pica command list widget (add mask, fix some issues)

Shader debugger improvements

Renamed "Iteration index" to the (hopefully) more intuitive "Cycle Index".
Added flexible space at the bottom of the widget.

Introduce a shader tracer to allow inspection of input/output values for each processed instruction.

Now supports dumping the current shader and recognizes a larger number of output semantics.

Handle `FileType::CIA` in `switch` statements

citra-qt: save path for recent files loaded

vfp: use std::swap where applicable

Handle invalid `Log::Class`

Vertex Shader JIT for X86-64

- Config: Add an option for selecting to use shader JIT or interpreter.
- Qt: Add a menu option for enabling/disabling the shader JIT.

- Also renames "vertex_shader.*" to "shader_interpreter.*"

Make `Loader::LoadFile` return an `ErrorNotImplemented` if you call
it on a CIA file.

Make `GetFileTypeString` return ‘CIA’ for CIA (CTR Importable
Archive) files.

Add a case of `Log::Class::Count` to the switch statement that
dispatches on `Log::Class`.  The case simply calls the `UNREACHABLE`
macro.

debugger: Add the ability to view VFP register contents

Stop defining GCC always_inline attributes as __forceinline