Renormalization issue in Kromer Plot

[unoebauer]

The current normalization of the Kromer plot only works if the binning used in the histogram encompasses the bulk of the escaping packets. Instead of

Lnorm = 0
for w in weights:
    Lnorm += np.sum(w)

the following expression should be used:

Lnorm = 0
for w, lam in zip(weights, lams):
    Lnorm += np.sum(w[(lam >= self.bins[0]) * (lam <= self.bins[-1])])

[jamesgillanders]

See PR #31