Use same constants for tests.

Make constants as static.
Remove copyright from Mp3FileTest.cpp.
Add script for debugging application.
Improve code base and documentation of MediaInit.

 * make init and deinit only if it is necessary.
 * make deinit in dtor of MediaInit.
 * add documentation to each method of MediaInit.
Use unique_ptr instead of shared_ptr for MediaInit.
Fix few issues which is related for GlobalTestEnvironment.

 * give it correct name;
 * remove useless code;
 * do not create MediaInit on heap;
 * update main and makefile according to changes.
Make initializing of core library in application.
Add documentation to MediaInformation class.
Add documentation and missed methods of MediaFile.
Remove needless copyrights.
Make formating and add const modifier in Playlist.
Make ptr const playlist and add documentation for CommonPlayer.
Remove useless copyrights in few files.
Add documentation for IconType enum.
Add extra line in definition of DirectoryState.
Add documentation for ItemIterator entity.
Return reference on shared_ptr on getting items from MediaContainer.
Add documentation to MediaContainer entity.
Add documentation to ObserverClient.
Add documentation to ObserverMediator.