[Testing] Develop manual tests

There are a lot of cases where human interaction and human vision on graphical elements are needed. Manual tests are needed for that purpose. These tests should be designed and properly stored. The following general steps are proposed to reach that:

1. A folder `manual` in `tests` folder to keep manual tests.
2. Each test should be described in a separate *.md file.
3. The list of tests should be reflected in a separate *.md file that will contain references to all these manual tests.
4. All small sub-programs that are needed to simulate required behavior should be placed in `manual\imitators`.

At the beginning, these tests should focus on UI part. The core functionality should be focus for unit-tests and system-tests.