Function: lfunlambda
Section: l_functions
C-Name: lfunlambda0
Prototype: GGD0,L,b
Help: lfunlambda(L,s,{D=0}): compute the completed L function Lambda(s),
 or if D is set, the derivative of order D at s. L is either
 an Lmath, an Ldata or an Linit.
Doc: compute the completed $L$-function $\Lambda(s) = N^{s/2}\gamma(s)L(s)$,
 or if \kbd{D} is set, the derivative of order \kbd{D} at $s$.
 The parameter \kbd{L} is either an \kbd{Lmath}, an \kbd{Ldata} (created by
 \kbd{lfuncreate}, or an \kbd{Linit} (created by \kbd{lfuninit}), preferrably the
 latter if many values are to be computed.

 The result is given with absolute error less than $2^{-B}|\gamma(s)N^{s/2}|$,
 where $B = \text{realbitprecision}$.
