Delaunay complex

[VincentRouvreau]

Fix #967

New Delaunay complex module:

• The Delaunay complex filtration values computed with different techniques:
  • Delaunay complex (without filtration values)
  • Delaunay Čech complex (using minimal enclosing ball technique)
  • Alpha complex (documentation moved in this new section)

New design of the python module:

classDiagram

Alpha_complex~Kernel, Weighted~ *-- Delaunay_complex_t~Kernel, Weighted~

Abstract_delaunay_complex <|-- Delaunay_complex_t
Abstract_delaunay_complex *-- Delaunay_complex_interface

Delaunay_complex_t : - Alpha_complex~Kernel, Weighted~ alpha_complex_
Delaunay_complex_interface : - unique_ptr~Abstract_delaunay_complex~ alpha_ptr_

Alpha_complex : - Alpha_kernel_d~Kernel, Weighted~ kernel_
Alpha_kernel_d~Kernel, Weighted~ *-- Alpha_complex

Alpha_kernel_d : - Kernel kernel_

(sorry for the branch name that is confusing - sklearn interface will come after)