pragma once and for all

Fix licenses

libsel4allocman: Return allocated objects to the correct pool

The split untyped allocator maintains three pools for different kinds of untyped
objects. Previously the origin of an object was not tracked and when the object
was freed (i.e. returned to the allocator) it was just put back into kernel only
untyped pool. This naturally corrupted the book keeping resulting in future
allocations failing. This change records which pool any allocation is sourced
from and returns back to that pool

libsel4allocman: Memory mapped device IO allocation support

Adds support at the top level allocman interface for allocating
objects at a particular physical address (allocman_utspace_alloc_at)
as well as fullfilling allocations from 'device memory'. Uses this
for implementing the additional vka interface function vka_utspace_alloc_at

The split and twinkle untyped allocators are updated to support this
new interface. split implements the 'alloc_at' by brute force searches
over its untypeds, whilst twinkle with its lack of book keeping
is forced to fail any 'alloc_at' request

libsel4allocman: Make allocman 64-bit friendly

When compiling for 32-bit there may be spurious warnings due to
some interface type changes. These will eventually be fixed when
other libraries are made 64-bit compatible