Clipped

Added thread class and a basic test.

Reworked tests. Create own files and directories to prevent messing up with linux/windows differences on ctest directory structure.

Fixed unexpected behaviour: Appending to path shall only store in this variable, if it is manually assigned to it in user code. Silently appending by reference is a bit spooky.

Fixed unexpected behaviour: touch shall not keep the file open. A reopened file afterwards causes a non working file handle (empty file on write).

Switched to recursive search.