missing declarations in Basis Splines

[florian]

Hi,

I could not run multiple examples from Basis Splines, e.g.: 
"https://www.gnu.org/software/gsl/doc/html/bspline.html#example-3-least-squares-and-breakpoints";,
 because
multiple documented functions could not be found in gsl include path (or 
gsl_bspline.h). Not found, but documented, functions are for example:
- gsl_bspline_ncontrol
- gsl_bspline_init_uniform
- gsl_bspline_wlssolve
- gsl_bspline_calc
- ...

Tested with gsl 2.7 from https://mirror.ibcp.fr/pub/gnu/gsl/gsl-latest.tar.gz 
and git://git.savannah.gnu.org/gsl.git
Tested with gsl 2.6.

Could not find any possible configure enable option within INSTALL or README 
files or from documentation.

Best regards
Flo