File headers updated and better context switching.

Overall Changes
---------------
- The way tasks yield upon an IPC system call has changed so now it
  is more performant. IPC is finally at a stage where performance is
  not an immediate issue.
- Tasks can retrieve the first message present in their message
  boxes. This removes constant checking for messages; thus, reducing
  the amount of system calls in total, while simplifying the code of
  tasks which act as services.
- Manual yielding is now less present in the various operating
  system programs.
- The PS/2 driver task and the terminal task have been re-enabled
  for the sake of showcasing the current stage of graphics and input.
- Likely resolved a file read deadlock when a file's byte size
  is a multiple of 256.
- Makefile variable bug fix for `make stats`.

Copyright Notice
----------------
- The file headers have had their copyright dates updated to match
  the current year (2021). Newlines have also been added to all
  text files.

Expanded system calls and added primative IPC.

Overall Changes
---------------
- Tasks can now identify other task's identities or self-identify
  themselves. This is further used for IPC purposes.
- The in-kernel threading support has been completely removed. In an
  attempt to be more esoteric, I am switching from a 1:1 model to a
  N:1 model instead, which means there will only be a concept of
  threads in user space and not inside the kernel itself.
- Tasks can load ELF files from the FAT16 partition; however, this is
  completely temporary and will only be limited to the initialisation
  task in the future.
- A task can increase its heap space by a single page (4 KiB) upon a
  specific system call. Currently, it's kept to only a single page to
  limit fragmentation, and consecutive frames are harder to come by.
- Tasks can send messages to other tasks via a vague sender and
  receiver setup with a notion of ports in between them. This is a
  multi-copy method of IPC and it uses SIMD registers (SSE "XMM"
  registers) to perform transfers. The buffer length is controlled
  inside the kernel and it is currently static.
- Symbols registered as functions in the assembly files and the
  assembly files themselves have been renamed to avoid preprocessing,
  as I see no use for it.
- A number of improvements to the various Makefiles in regard to
  organisation, operating system files, and the drive image.
- Updated the supplied OVMF firmware and GNU-EFI object.

Git Notice
----------
- Commits will no longer be made for version changes. It will be
  solely done through tags now.
- These types of bulk commits may happen less now, as the focus is
  beginning to be solely on the operating system programs
  themselves, along with system call functionality.

V00-11-00

Overall Changes
---------------
- The minor version has been increased.

V00-10-00

Overall Changes
---------------
- The minor version has been increased.

Version change.

The last bulk update.