Oimodeler

Basic features of the oimodeler package are almost fully implemented although not fully tested and verified.

Still Missing :
- Components & models : Exploration of grid of models, binary orbit, rotating star, temperature gradient disk, blackbody-based flux interpolator, saving of model and parameters
- Fitter : Levenberg-Marquardt fitter with various global search patterns, more options for the emcee-base fitter, chain of fitters, saving fitter & results

Implementation of a generic Image-plan component that can be sub-classed to build component using a internal function or and external image or function.

Added fitter, examples and doc.

Analytical models in the Fourier space are implemented with chromaticity and the simulator allows to load oifits data, simulate data at the same spatial frequencies and computed chi2 between data and model. Basic plotting functions have been implemented.