BuildSystem: Cleanup userspace directory layout

userspace programs are now in userspace/programs
userspace tests are now in userspace/tests

This makes listing userspace projects much cleaner. Libraries were
already separated to their own directory, so other programs should also.

userspace/programs/WindowServer/Framebuffer.cpp

@@ -0,0 +1,45 @@
+#include "Framebuffer.h"
+
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/framebuffer.h>
+#include <sys/mman.h>
+
+Framebuffer open_framebuffer()
+{
+	int framebuffer_fd = open("/dev/fb0", O_RDWR);
+	if (framebuffer_fd == -1)
+	{
+		perror("open");
+		exit(1);
+	}
+
+	framebuffer_info_t framebuffer_info;
+	if (pread(framebuffer_fd, &framebuffer_info, sizeof(framebuffer_info), -1) == -1)
+	{
+		perror("pread");
+		exit(1);
+	}
+
+	const size_t framebuffer_bytes = framebuffer_info.width * framebuffer_info.height * (BANAN_FB_BPP / 8);
+
+	uint32_t* framebuffer_mmap = (uint32_t*)mmap(NULL, framebuffer_bytes, PROT_READ | PROT_WRITE, MAP_SHARED, framebuffer_fd, 0);
+	if (framebuffer_mmap == MAP_FAILED)
+	{
+		perror("mmap");
+		exit(1);
+	}
+
+	memset(framebuffer_mmap, 0, framebuffer_bytes);
+	msync(framebuffer_mmap, framebuffer_bytes, MS_SYNC);
+
+	Framebuffer framebuffer;
+	framebuffer.fd = framebuffer_fd;
+	framebuffer.mmap = framebuffer_mmap;
+	framebuffer.width = framebuffer_info.width;
+	framebuffer.height = framebuffer_info.height;
+	framebuffer.bpp = BANAN_FB_BPP;
+	return framebuffer;
+}