Move keypoint

[kekeblom]

Implements moving keypoints. The tool api is starting to take shape. Basically the controller is always responsible who handles an event. The event handlers return true if they think that the event has been handled and should not be handled by someone else. It is however at the controllers discretion, whether this wish is respected.

Still todo before merging:

• [x] write test case for move keypoint command
• [x] write test case for move keypoint tool

[kekeblom]

Currently the same mesh shader is being loaded and compiled in different places. Maybe we can create an issue to be fixed later. Basically, it would be better if there was a ShaderLibrary singleton or something that loaded if needed and just returned a handle to the shader if it has already been loaded and compiled.

[kekeblom]

Added test cases.