ci = ciquant(x,p,C);
Input C is confidence level for the interval (default 0.95),
p is the probability that define quantile,
x is a sample; if x is a matrix, the procedure
is colonwise.
The interval ci is of the form
[LeftLimit, PointEstimate, RightLimit]'.
The interval is constructed conservatively in both ends,
that is P(q<LeftLimit) <= C/2 and similarly for the upper limit.
See also QUANTILE.