Right now only MappedBuffers that only span a single page and are not aligned are implemented.
MappedBuffers are unmapped during the reply part of ReplyAndReceive. Only unmapping of ReadOnly buffers is currently implemented.
The code now properly configures the process image to match the loaded
binary segments (code, rodata, data) instead of just blindly allocating
a large chunk of dummy memory.
This enables more dynamic management of the process address space,
compared to just directly configuring the page table for major areas.
This will serve as the foundation upon which the rest of the Kernel
memory management functions will be built.