remove debug output from layout engine
add vender prefix to CSS animation
add SVGAnimateElement cache
fix layout
add 'set scale' command
Surpress plugin overloading
enable scaling by mouse wheel
add NodeView#GteCenterGX/GY
fix Viewport constructino
fix menu position
change undeveloped-goal layout
fix layout for undeveloped goal
add Viewport#PageX/YFromGX/Y method
fix problem that draging is canceled by crossing node
invoke folding when a node is doubleclicked
refactor css and prohibit selected text
merging