Add Pythagoras Tree Fractal

Fix build error with custom comparator in EventHandler

Fix small display issues

Add mouse button releasing action for all widgets when the window loses focus

Refactor event triggering mechanism, remove vector sorting from it

Add priority in widgets events triggering

Fix platform Select widget display issue

Add Burning Ship Fractal

Fix bugs

Add selected device information querying

Add Select Widget and extend abstartion division of OpenCL

Implement Julia Set Fractal

Modify Mandelfract kernel argumets to gain more flexability

Add error handling mechanisms

Edit context creation for different CL platforms