Added various possible camera models for the photometric and response calibration

[AlbertoJaenal]

Main changes:

• The camera models code was copied from the DSO repository and changed to fit in the process.
• The results are saved in the folder of the camera.

Examples:

FishEye (EquiDistant) camera. Sequence: calib-vignette3 (512x512) (download) from Calibration Sequences from https://vision.in.tum.de/data/datasets/visual-inertial-dataset

FOV (RadTan) camera. Sequence: narrowGamma_vignette (download) from Calibration Sequences from https://vision.cs.tum.edu/data/datasets/mono-dataset

[NikolausDemmel]

Thanks, this is useful. However, one issue with merging this is that the DSO code is GPL, and these tools here are currently licensed under BSD...