now experimental gtk3 flag added.
hoodle is buildable with GTK3. not runtime tested yet.
add missing CPP Language extension for making it compilable with gtk2
remove unnecessary c routines
compilable with gtk3
find culprit of crash in gtk3 run
consistently use doIOaction
LICENSE for hoodle-render and hoodle-core to BSD3
Merge branch 'gtk3' into master-gtk3

Conflicts:
	hoodle-core/hoodle-core.cabal
	hoodle-core/src/Hoodle/Coroutine/Default.hs
	hoodle-core/src/Hoodle/Coroutine/Draw.hs
	hoodle-core/src/Hoodle/Coroutine/File.hs
	hoodle-core/src/Hoodle/Coroutine/HandwritingRecognition.hs
	hoodle-core/src/Hoodle/Coroutine/Link.hs
	hoodle-core/src/Hoodle/Coroutine/Minibuffer.hs
	hoodle-core/src/Hoodle/Coroutine/TextInput.hs
	hoodle-core/src/Hoodle/Coroutine/VerticalSpace.hs
	hoodle-core/src/Hoodle/Coroutine/Window.hs
	hoodle-core/src/Hoodle/GUI.hs
	hoodle-core/src/Hoodle/GUI/Menu.hs
	hoodle-core/src/Hoodle/GUI/Reflect.hs
	hoodle-core/src/Hoodle/ModelAction/Layer.hs
	hoodle-core/src/Hoodle/ModelAction/Window.hs
	hoodle-core/src/Hoodle/Type/Canvas.hs
	hoodle-core/src/Hoodle/View/Coordinate.hs
	hoodle-core/src/Hoodle/View/Draw.hs
	hoodle-render/hoodle-render.cabal
make hoodle compilable with gtk3. it runs but canvas size is wrong yet.
hoodle is compilable both with gtk2 and with gtk3! gtk2 hoodle works as it is supposed to do!