Merge pull-request #27 from sbelsky:hotfix/restore_tests to master

Hotfix/restore tests
restore all test cases except ```test_running``` "suite" because this is not unit-test (by definition). i think ```test_running``` is a at least integration test or simple Example of ```dir_monitor``` async usage.

The job has been made under Win8.1/VS2013 (my native workstation) and Ubuntu12.01/gcc-5.2.1 (which is the same as in travis-ci build server).
[CI results](https://travis-ci.org/sbelsky/dir_monitor)

Unfortunately i'm not familiar with MacOS at all. So tests under this OS were not provided. Hope somebody will do it.

[close #27]