Add back X11 support to EGL

Refactor the EGL backend to provide a platform separation here, which is
better abstracted away than the old EGL/X11 implementation.

Source/Core/DolphinWX/GLInterface/EGLX11.cpp

@@ -0,0 +1,34 @@
+// Copyright 2014 Dolphin Emulator Project
+// Licensed under GPLv2
+// Refer to the license.txt file included.
+
+#include "DolphinWX/GLInterface/EGLX11.h"
+
+EGLDisplay cInterfaceEGLX11::OpenDisplay()
+{
+	dpy = XOpenDisplay(nullptr);
+	XWindow.Initialize(dpy);
+	return eglGetDisplay(dpy);
+}
+
+EGLNativeWindowType cInterfaceEGLX11::InitializePlatform(EGLNativeWindowType host_window, EGLConfig config)
+{
+	EGLint vid;
+	eglGetConfigAttrib(egl_dpy, config, EGL_NATIVE_VISUAL_ID, &vid);
+
+	XVisualInfo visTemplate;
+	visTemplate.visualid = vid;
+
+	XVisualInfo *vi;
+	int nVisuals;
+	vi = XGetVisualInfo(dpy, VisualIDMask, &visTemplate, &nVisuals);
+
+	return (EGLNativeWindowType) XWindow.CreateXWindow((Window) host_window, vi);
+}
+
+void cInterfaceEGLX11::ShutdownPlatform()
+{
+	XWindow.DestroyXWindow();
+	XCloseDisplay(dpy);
+}
+