Distinguishing drawables in the scene + refactoring

GUI/src/main/java/cz/fidentis/analyst/gui/canvas/Canvas.java

...n/java/cz/fidentis/analyst/gui/canvas/CanvasListener.java

...ain/java/cz/fidentis/analyst/gui/core/ControlPanelTC.java

...src/main/java/cz/fidentis/analyst/gui/scene/Drawable.java

...main/java/cz/fidentis/analyst/gui/scene/DrawableFace.java

.../cz/fidentis/analyst/gui/scene/DrawableFeaturePoints.java

...main/java/cz/fidentis/analyst/gui/scene/DrawableMesh.java

...ain/java/cz/fidentis/analyst/gui/scene/DrawablePlane.java

GUI/src/main/java/cz/fidentis/analyst/gui/scene/Scene.java

...ain/java/cz/fidentis/analyst/gui/scene/SceneRenderer.java

.../main/java/cz/fidentis/analyst/gui/tab/SingleFaceTab.java

.../cz/fidentis/analyst/gui/toolbar/RenderingModeAction.java

...ava/cz/fidentis/analyst/gui/toolbar/RenderingToolBar.java

...va/cz/fidentis/analyst/gui/toolbar/SingleFaceToolBar.java

...dentis/analyst/registration/PostRegistrationListener.java

...fidentis/analyst/registration/PostRegistrationTestTC.java

...main/java/cz/fidentis/analyst/symmetry/SymmetryPanel.form

...main/java/cz/fidentis/analyst/symmetry/SymmetryPanel.java

...ava/cz/fidentis/analyst/symmetry/SymmetryPlaneAction.java

GUI/src/main/resources/symmetry28x28.png