Hook up multiview camera calibration to CRPs

[mleotta]

Add an option (e.g. menu item, button) to estimate multiple cameras and GCP 3D locations from a collection of 2D CRPs. This should be done by passing the "tracks" from the CRPs to the KWIVER initialize_cameras_landmarks API. Configuration for this algorithm should be read from an installed config file that is different from the existing "gui_initialize.conf" but could initially contain the same content. The computed landmark locations should be used to set the GCP locations.