-Add minimize functionality
->minimize only works when the DockNode is floating
->minimize calls iconify function
-Fix a bug causing the docknode to disappear (Linux Mint 64 bits, java 8 Oracle)
->appears when the user drag a docknode outside, then maximize the floating node and maximize again the floating node
-Add minimize functionality ->minimize only works when the DockNode is floating ->minimize calls iconify function
-Fix a bug causing the docknode to disappear (Linux Mint 64 bits, java 8 Oracle) ->appears when the user drag a docknode outside, then maximize the floating node and maximize again the floating node