Mccn trainer

• Adds num_worker option to trainer
• Adds a logger to save losses, images, and gradients which can be visualized with tensorboard
• Adds a new architecture of mccnn with shared layers, MCCNNv2 and its extractor
• Added a RandomHorizontalFlipImage class for Multi channel images which works with numpy.ndarrays (solves the requirement to transform to PIL image for using the torchvision version, which doesnt work for num_channels>4)