address-space is a non-recursive data structure, which contains a flat list of vm_areas representing
mapped vm-objects.
userspace programs can no longer create sub-address-spaces. instead, they can reserve portions of
the address space, and use that reserved space to create mappings.
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.
this allows the object header to be placed anywhere within the larger
object structure.
the object system now also ensures that the object is zero-initialised
during allocation.