[Eric] Unittest fixes

[Mikhail Terekhov]

Detlev,


Please conside the following fixes for unittest:

    - Fix unittests discovery in any subfolder of the project

    - Allow unittests for projects without main script

    - Recursively change children's check state when an item check state
is changed in the unittest discoveryList.

The bandle of the fixes is attached.

BTW may be it makes sense to move "Unittest Project.." from "Extra" to
"Project-Tools" menu?


Regards,

Mikhail