Add bin/uname, fix disk buidling

Disk will now rebuild when userspace/*.c are updated.
Make sure you build in userspace/ first!

Makefile

@@ -132,7 +132,7 @@ initrd/boot/kernel: toaruos-kernel
 hdd:
 	@mkdir hdd
 
-toaruos-disk.img: hdd hdd/bs.bmp
+toaruos-disk.img: hdd hdd/bs.bmp userspace/*.c
 	@${BEG} "hdd" "Generating a Hard Disk image..."
 	@-rm -f toaruos-disk.img
 	@${GENEXT} -d hdd -q -b 131072 -N 4096 toaruos-disk.img ${ERRORS}

userspace/uname.c

@@ -0,0 +1,15 @@
+/* vim: tabstop=4 shiftwidth=4 noexpandtab
+ *
+ * uname
+ */
+#include <stdio.h>
+#include <syscall.h>
+
+DEFN_SYSCALL1(kernel_string_XXX, 25, char *);
+
+int main(int argc, char * argv[]) {
+	char _uname[1024];
+	syscall_kernel_string_XXX(_uname);
+
+	fprintf(stdout, "%s\n", _uname);
+}