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/sleep/CMakeLists.txt

@@ -0,0 +1,8 @@
+set(SOURCES
+	main.cpp
+)
+
+add_executable(sleep ${SOURCES})
+banan_link_library(sleep libc)
+
+install(TARGETS sleep OPTIONAL)

userspace/programs/sleep/main.cpp

@@ -0,0 +1,38 @@
+#include <ctype.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+int usage(char* argv0, int ret)
+{
+	FILE* fp = (ret == 0) ? stdout : stderr;
+	fprintf(fp, "usage: %s SECONDS\n", argv0);
+	return ret;
+}
+
+int main(int argc, char** argv)
+{
+	if (argc != 2)
+		return usage(argv[0], 1);
+
+	if (strlen(argv[1]) > 9)
+	{
+		fprintf(stderr, "SECONDS argument too large\n");
+		return usage(argv[0], 1);
+	}
+
+	int seconds = 0;
+	const char* ptr = argv[1];
+	while (*ptr)
+	{
+		if (!isdigit(*ptr))
+		{
+			fprintf(stderr, "invalid SECONDS argument\n");
+			return usage(argv[0], 1);
+		}
+		seconds = (seconds * 10) + (*ptr - '0');
+		ptr++;
+	}
+
+	sleep(seconds);
+}