Function: qfrep
Section: linear_algebra
C-Name: qfrep0
Prototype: GGD0,L,
Help: qfrep(x,B,{flag=0}): vector of (half) the number of vectors of norms
 from 1 to B for the integral and definite quadratic form x. Binary digits of
 flag mean 1: count vectors of even norm from 1 to 2B, 2: return a t_VECSMALL
 instead of a t_VEC

