Digital user input and HID module implementation for PAD

loader.cpp: improved file extension checking, made Upper/LowerStr useful, moved string_util into Common namespace

Prune redundant includes

Removed fixed_size_queue.h

Common: Fix a potential infinite loop in StringUtil's ReplaceAll

Common: Remove HAVE_CXX11_SYNTAX define from Common.h

It's unused and doesn't look like it compiles anyway :/

Instead of forcibly taking the last 4 characters, it now finds the last extension separator (the period) and takes a substr of its location.

core: Make the ARM disassembler use std::string internally

Removed redundant headers for std implementations

core: Pass string by reference in FetchFromPortName and DeleteService

Minor cleanup in ncch.

In C++ you can simply just declare it as is.

Removed common/atomic, instead using std::atomic

Removed the need for X11 on OS X

It only causes issues when someone (who doesn't need it) doesn't have it.

CMake cleanup

Several cleanups to the buildsystem:
 - Do better factoring of common libs between platforms.
 - Add support to building on Windows.
 - Remove Qt4 support.
 - Re-sort file lists and add missing headers.

This should fix the GL loading errors that occur in some drivers due to
the use of deprecated functions by GLEW. Side benefits are more accurate
auto-completion (deprecated function and symbols don't exist) and faster
pointer loading (less entrypoints to load). In addition it removes an
external library depency, simplifying the build system a bit and
eliminating one set of binary libraries for Windows.

Fix GPU/HW synchronization

Introduce VAddr and PAddr typedefs for ARM addresses.

GPU: Improve frame synchronization, increases compatibility with both homebrew and retail applications.