Objects on structure tree.
Object deleting on structure tree.
Simple object properties.
Poprawa literowki
Dodanie popup menu do preview
Merge branch 'kvasnyk' of https://github.com/lechoPl/GameMaker into pawel

Conflicts:
	GameMakerEditor/src/gui/gameview/LevelPreview.java
Dodanie odswiezanie structuretree
Dodany dwuklik