Improvements to convergence time functions.

[Datseris]

Add new function convergence_and_basins_fractions, and improve the algorithm counting the convergence iterations for AttractorsViaRecurrences to give more accurate results, by taking into account the user-provided convergence criteria.

To make it possible i added one more field on the basin info struct that contains a return code that tells us how the recurrences map ended.

[awage]

Nice one! I didn't spotted these inconsistencies! The only mismatch will happen with the :bas_hit state has been reached. In this case you cannot know the convergence because the trajectory has not converged to the attractor yet. Nevertheless, if accuracy is an issue, setting consecutive_basin_steps to a high number does the trick.

I have seen the code and just made a suggestion. I can try to set up a test if you need it.

[Datseris]

If you wish to contribute a test that indeed would be fantastic!

[Datseris]

I also realized that in the case of the Proximity Mapper, we return the actual convergence time, not iteration number. While in the recurrences we return the iteration number instead. We have to harmonize this.

First, we need to rename this function to convergence_time and second, for the recurrences we need to return the iteration multiplied by the internal; Δt. I will do this change now.