Implement saving world description to file
Implement SymEnt::Serialize, remove duplicate code
Fix memleak: Add virtual destructor to SymEnt
Implement reading world description from file
Init map editor implementation
Draw rectangles in MapEditor
Create simple menu in MapEditor to choose item to draw
Fix bug: incorrect shape ids set in constructors
MapEditor: Implement saving world to file

Right now only RectangleEnt's are supported
MapEditor: Use command design pattern, implement AddRectangularEntCommand, ask user for params
MapEditor: Show selection region during drawing
MapEditor: implement CicrcularEnt support
MapEditor: Add support for KheperaRobot
MapEditor: Use save file dialog
Symulator: user can set symulation step and delay
Visualiser: Draw robot's wheels
Use cartesian coordinates system, improve collision handling
Merge branch 'world-description-file' into master

Implement world serialization to file and start working on map editor
Conflicts:
	KheperRobotSymulation/KheperRobotSymulation.vcxproj.filters
	KheperRobotSymulation/RectangularEnt.cpp
	KheperRobotSymulation/RectangularEnt.h
	KheperRobotSymulation/Symulation.cpp
	KheperRobotSymulation/Symulation.h
	KheperRobotSymulation/main.cpp
	Visualiser/Visualiser/Visualiser/KheperaRobot.cs
	Visualiser/Visualiser/Visualiser/SymEnt.cs
Fix robot wheels drawing

For initial implementation of robot's wheels drawing see
343c941b2d60f492c9cf3b6038585b089e299b29
Begin writing test and implementing RectangularEnt serialization