First code for Interfaces
Adding a test file for FileReaderManager
Retrieving Reader by extension working
Priorizing FIleReaderInterfaces now works
Readers Manager can now handle options
Cpmplete Implementation of Reader Manager, far more extensive testing.
Const-Pointer in method headers
Extracted FileReader Interface and created new abstract class. Moved some files to better directories.
Using common Service Ranking instead of private service Priority
FileName handling now in abstract superclass
Exchanged const char * with std::string for filenames, patters etc.
More trivial methods implemented in Abstract FileReader. Test now operates on Abstract FileReader instead of the Interface.
Moved Microservice Registration Logic to Abstract Class
Applied context trick to all ReaderManager Methods. This way, The user can just call the methods without aquiring a ReaderManager, but still the correct context is used.
Somem ore default implementations for Abstract Class
Const-Changes from szelzer's advise
AbstractFileReader does not inherit from lightobject anymore. Inheriting classes have to inherit from lightobject if they want the reader to be registered as a Microservice.

Also: Some code cleaning
Removed Read from memory methods, as they are being replaced by Read from InputStream Method
Changed Filenames according to convention
Renamed Microservice Related String Constants Prefix from US_ to PROP_