backend: defaulted move constructor/assignment

services: minor changes 

OpenGL: Downgrade GL_DEBUG_SEVERITY_NOTIFICATION to Debug logging level

The nVidia driver is *extremely* spammy on this category, sending a
message on every buffer or texture upload, slowing down the emulator and
making the log useless.

Memory: Implemented MMIO

color: Make trivial helpers constexpr

Shader JIT: Fix off-by-one error when compiling JMPs

Shader: Implement "invert condition" feature of IFU instruction

Debugger: Use 3dbrew names for GPU registers

elf: Don't cast away const

key_map: Use std::tie for comparisons

archive_backend: Remove unnecessary const from return types

This doesn't return by reference so const isn't really necessary

This list was imported from the 3dbrew wiki page and is pretty much
complete.

If the bit 0 of the JMPU instruction is set, then the jump condition
will be inverted. That is, a jump will happen when the boolean is false
instead of when it is true.

There was a mistake in the JMP code which meant that one instruction at
the destination would be skipped when the jump was taken. This commit
also changes the meaning of the culprit parameter to make it less
confusing and avoid similar mistakes in the future.

hwrasterizer: Use depth offset

DisassembleMemHalf: actually use width in determining opcode name

command_processor: Get rid of variable shadowing

HLE/SVC: Implement UnmapMemoryBlock.

This implementation will need to be (almost completely) changed when we implement multiprocess support.

Add optional GL_KHR_debug support

Not much thought went into that one...

HLE/Sockets: Fixed the buffer offset in recvfrom.

Update appveyor.yml to use VS2015 CMake generator

Gamelist: supply default settings for QSettings config