0.75.0

• Added a channel mask feature to GafferImageUI::ImageView. Use the r,g,b and a keys to isolate individual channels (#403).
• Updated for compatibility with Cortex 8.0.0a14.
• Updated screengrab app to allow the execution of a commands file.
• Added a node find dialogue, accessible via the Edit/Find.. menu item (#454).
• Added NodeGraph.frame( nodes ) method. This can be used to frame specific nodes within the viewport of the NodeGraph.
• Addressed thread related hangs when using an InteractiveRenderManRender and deleting or connecting nodes.