some updates:
-spline --> interpolate: a more compact module for interpolation.
-tools_bethe --> functions_bethe: Bethe Lattice related functions moved into FUNCTIONS with
some density of states and gaussian.
-some improvements in STATISTICS for histogram routines
Merge branch 'devel'

Conflicts:
	lib/libscifor.a
	lib/libscifor_deb.a
	src/Makefile