Started to work on AArch64 version.
Written code for generating raw kernel binary.
The kernel prints a character.
Now the kernel prints "Hello World!".

- Various fixes in build scripts.
- Assembly->C++ transition is done.
Implemented logging.

1. Refused to use dedicated assembly files (only inline).
2. Implemented device-independed logger class.
3. Fixed issue with FP and SIMD (disabled traps).
4. Reorganized code tree.
5. Modified README.md.