[util] Replace kutil with util

Now that kutil has no kernel-specific code in it anymore, it can
actually be linked to by anything, so I'm renaming it 'util'.

Also, I've tried to unify the way that the system libraries from
src/libraries are #included using <> instead of "".

Other small change: util::bip_buffer got a spinlock to guard against
state corruption.

src/kernel/objects/vm_area.h

@@ -5,9 +5,9 @@
 #include <stddef.h>
 #include <stdint.h>
 
-#include "enum_bitfields.h"
-#include "j6/signals.h"
-#include "kutil/vector.h"
+#include <j6/signals.h>
+#include <util/vector.h>
+#include <enum_bitfields.h>
 
 #include "kernel_memory.h"
 #include "objects/kobject.h"
@@ -18,7 +18,7 @@ class vm_space;
 enum class vm_flags : uint32_t
 {
 #define VM_FLAG(name, v) name = v,
-#include "j6/tables/vm_flags.inc"
+#include <j6/tables/vm_flags.inc>
 #undef VM_FLAG
     driver_mask     = 0x000fffff, ///< flags allowed via syscall for drivers
     user_mask       = 0x0000ffff, ///< flags allowed via syscall for non-drivers
@@ -74,7 +74,7 @@ protected:
 
     size_t m_size;
     vm_flags m_flags;
-    kutil::vector<vm_space*> m_spaces;
+    util::vector<vm_space*> m_spaces;
 
     // Initial static space for m_spaces - most areas will never grow
     // beyond this size, so avoid allocations
@@ -165,7 +165,7 @@ public:
     virtual bool get_page(uintptr_t offset, uintptr_t &phys) override;
 
 private:
-    kutil::vector<uintptr_t> m_cache;
+    util::vector<uintptr_t> m_cache;
     uintptr_t m_start;
     size_t m_pages;
     uintptr_t m_next;