This adds some structures necessary to support multiple memory regions
in the future. It also adds support for different system memory types
and the new linear heap mapping at 0x30000000.
memory.cpp/h contains definitions related to acessing memory and
configuring the address space
mem_map.cpp/h contains higher-level definitions related to configuring
the address space accoording to the kernel and allocating memory.
Yuri Kunde Schlesner
Emmanuel Gil Peyrot