New histogram function names, decration of older names

Datseris released this 12 Jan 15:17

3177aa4

Histograms (#35)

* clean rqa code

* error > throw(ErrorException())

* optimization of histogram functions

* Poincare recurrence times and RT parameters

* minimum lenght line for histograms

* add `recurrencestructures`

* add tests

Assets 2