[#3] New test data for 15x15

+ added tests 3, 4, 7 and 8
[#6] Enhance test runner

For test runner script run_test.py:
- implement run for all tests and for individual tests
- add documentation to the script
[#6] Support test module in test runner

Test runner script can run single test, test module, or all tests.
Example of command for test runner:
- single test:
    ./run_tests.py logimage_15_15.test_2_nomade
- test mdoule:
    ./run_tests.py logimage_15_15
- all tests:
    ./run_tests.py