Graphinglib

New plottable objects in this version

- Heatmap
- VectorField
- Multifigure (and Subfigure)

New features in this version

- Curve arithmetics
- Curve integration and differenciation
- Curve intersection
- Many other curve utilities

Minor bug fixes and improvements

- Possibility to create multiple figures and display them one at a time
- Improved behaviour in Jupyter Notebooks
- Many other bug fixes and improvements

What's Changed
* Removed the obligation to specify error on x and y axis to add error bars on curves and scatters
* Added possibility to write a label to a point while still displaying the coordinates
* Correcting bug caused by Text entry absent in default styles

This is the first release. Available classes are:
- Curve
- Scatter
- Histogram
- Heatmap
- Figure
- FitFromExponential, FitFromGaussian, FitFromLog, FitFromPolynomial, FitFromSine, FitFromSquareRoot, FitFromFunction
- Hlines, Vlines
- Point
- Text