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.

init/main.c

@@ -1,18 +1,20 @@
-#include <mango/arg.h>
-#include <mango/bsp.h>
-#include <mango/clock.h>
-#include <mango/cpu.h>
-#include <mango/handle.h>
-#include <mango/init.h>
-#include <mango/input.h>
-#include <mango/libc/stdio.h>
-#include <mango/machine/init.h>
-#include <mango/object.h>
-#include <mango/panic.h>
-#include <mango/printk.h>
-#include <mango/sched.h>
-#include <mango/test.h>
-#include <mango/vm-object.h>
+#include <kernel/arg.h>
+#include <kernel/bsp.h>
+#include <kernel/channel.h>
+#include <kernel/clock.h>
+#include <kernel/cpu.h>
+#include <kernel/handle.h>
+#include <kernel/init.h>
+#include <kernel/input.h>
+#include <kernel/libc/stdio.h>
+#include <kernel/machine/init.h>
+#include <kernel/object.h>
+#include <kernel/panic.h>
+#include <kernel/port.h>
+#include <kernel/printk.h>
+#include <kernel/sched.h>
+#include <kernel/test.h>
+#include <kernel/vm-object.h>
 #include <stdint.h>
 
 extern unsigned long get_rflags(void);