* initial implementation of billiard walk

* improved billiard completed for H-polytopes

* modify v-polytopes and zonotopes to be used by improved billiard walk

* update polytope intersection ball to be used by new billiard walk

* update point and volume rcpp function

* expose improved billiard to sample_points R function

* fix bugs including header in rcpp interface

* fix compile bugs in compute_reflection of ball.h

* update contribution comments in new header file

* update contribution comments in new header files

* implement svd rounding and create new folder for preproccessing methods

* update rounding interface in R to use the new method

* remove unused comments and improve R interface

* update roxygen comments

* implement interior point method to compute the chebychev ball

* implement maximum volume enclosed ellipsoid method

* implement rounding based on mve method

* fix errors in mve rounding

* fix default random walk in volume computation, remove unused comments

* update Rcpp function volume

* implement extraction of low dimensional polytope

* improve full dimensional polytope extraction

* create Aeq in Rcpp module of Hpolytope and import it in Rcpp rounding function

* improve computation of null space

* fix c++ tests

* add return variables-matrices for low dimensional polytopes

* expose in R get_full_dimensional_polytope

* fix compile errors

* improve stability on qr decomposition and fix bugs in rounding a low dimensional polytope

* improve stopping criterion in maxx_inner_ball computation

* improve full dimensional computation

* minor improvements and update roxygen comments in volume.cpp

* improve R interface in volume.cpp

* remove unused comments

* improve r interface in sample_points.cpp

* improve mve rounding

* fix compiler errors

* improve computation of AA in billiard

* improve eigenvalue computation and fix compiler errors

* improve code comments

* fix compiler error and update roxygen comments

* update copyright comments

* fix R tests and update documentation

* remove unused comments and update roxygen comments and Rd files

* add polishing comments and improve function names

* improve rounding options in R-proj/volume.cpp

* update rd files

* fix c++ tests and update rd files

* fix R tests

* fix R tests

* PR comments: improve names, variable names and declaration.

* change number of varialble inputs in rounding

* use std::tuple on rounding algorithms