Feature, ability to load playlist from other place.

-it's in development stage and not final code.
Final code for support user's playlists.
-No GUI implementation, yet.
-also some code cleanup
[No Code Change] More code clean-up
Improved, better  "removeFromPlayList()" and "playListContains()".

-"removeFromPlayList()" remove from all playlists some not
   specified.
-"playListContains()" firstly search through current
   playlist.
-some code clean-up
Feature, GUI part for user's playlist was implemented.