Calibrate now calculates the coefficients using Eigen.

The coefficients are calculated using the linear algebra libray called
Eigen. They are calculated by using the polynomial regression algorithm
described on the Wikipedia page called "Polynomial Regression".
Merge branch 'dev' of https://github.com/YaleIGVC/IGVC2014 into dev

Conflicts:
	src/image_unwarp/src/calibrate.cpp