Update mouse icons: use Farm-fresh icons by FatCow Web Hosting
http://fatcow.com/free-icons/

https://www.iconfinder.com/icons/64478/mouse_icon#size=32
https://www.iconfinder.com/icons/64479/left_mouse_select_icon#size=32
https://www.iconfinder.com/icons/64481/mouse_scroll_select_icon#size=32
https://www.iconfinder.com/icons/64480/mouse_right_select_icon#size=32
https://www.iconfinder.com/icons/35774/bullet_delete_icon#size=32
(#16)
Optimize icons size using PNGOut
(related to #16)
Add source for icons
(#16)
Add 32x32 icons for Australis and use them for popup notifications
(#16)