star identification

*recurrent neural network* cnn using libstarid cpp eigen kernel and tensorflow training and inference

*convolutional network* cnn using libstarid cpp eigen kernel and tensorflow training and inference

*triangles* find star triangles in the image, and candidate stars that meet the constraints implicit within the triangle. these constraints are effectively the rules for candidate stars. for example, if a triangle consists of star pairs ab and bc, then the third side is ac.