Meta: Add demo video to the project

Meta: Add demo video to the project

Meta: Add demo video to the project

Userland: Resolve issue in editor

Now, the entire system appears to be functional.  It's quite buggy
though.

Kernel: Resolve the deadlock issue

The cause was, that I was using a KernelMutex for the debug stuff, that
didn't really make sense and was unnecessary.

In the future, I will need to do this properly, however, that will
require careful considerations, about which actions can occur in
interrupt handlers.

However, I immediatelly ran into the next issue with the page allocator.

Kernel: Encounter another deadlock

I think we do not wake up after 'sys$read'.

Kernel: Remove incorrect assertion about reference count of default t…

…hread

This was a dangerous assertion and some code (in this case holding a
mutex) caused the reference count to be higher.

Kernel: Resolve issue with double stashing

Turns out, I forgot to clear the 'm_active_thread' when something
blocked.

Kernel: Execute the system calls

This appears to be working for the first system call, but the second one
seems to fail.

Kernel: Handle system calls in special SystemHandler thread

This thread will simply be responsible to spawn an actual worker thread
that completes the request.