Add comments & code clean & refectoring

...playpad/viewcontroller/dialog/DuplicateProjectDialog.java

...obias/playpad/viewcontroller/dialog/NewProjectDialog.java

...s/playpad/viewcontroller/dialog/ProjectManagerDialog.java

PlayWallCore/.gitignore

PlayWallCore/src/de/tobias/playpad/project/Importable.java

...Core/src/de/tobias/playpad/project/ProfileChooseable.java

PlayWallCore/src/de/tobias/playpad/project/Project.java

...lCore/src/de/tobias/playpad/project/ProjectReference.java