getDimQS
Usage: [D[,D2]] = getDimQS(A)
get full dimension of given QSpace object.
In case of non-abelian symmetries, usage #2 returns
number of multipets as D, and the full state space
dimension as 2nd argument D2.
NB! if no second output argument (D2) is requested,
this routine returns D if D==D2 (e.g. which is always
the case of abelian symmetries) but [D;D2] if D!=D2.
(C) AW : May 2006 ; Oct 2014