kernel: separate headers into kernel and user headers

all kernel headers have been moved from include/mango to include/kernel
and include definitions that are only relevant to kernel-space.

any definitions that are relevant to both kernel- and user-space
(i.e. type definitions, syscall IDs) have been moved to
include/mango within libmango.

vm/zone.c

@@ -1,12 +1,12 @@
-#include <mango/locks.h>
-#include <mango/util.h>
-#include <mango/queue.h>
-#include <mango/memblock.h>
-#include <mango/types.h>
-#include <mango/vm.h>
-#include <mango/printk.h>
-#include <mango/libc/string.h>
-#include <mango/machine/cpu.h>
+#include <kernel/locks.h>
+#include <kernel/util.h>
+#include <kernel/queue.h>
+#include <kernel/memblock.h>
+#include <kernel/types.h>
+#include <kernel/vm.h>
+#include <kernel/printk.h>
+#include <kernel/libc/string.h>
+#include <kernel/machine/cpu.h>
 
 static struct vm_page *group_pages_into_block(struct vm_zone *z, phys_addr_t base, phys_addr_t limit, int order)
 {