z-function evaluating to infinity

Moved this out of a random TODO file. Need to see if any of this is still relevant.

We currently don't throw errors if the z-function evaluates to infinity. This causes some weird results, like the parameters lambda = exp(5.25), nu = 0.4 always causing rcmp to draw 203 as the value.

Add ymax as an option (not global) to regression functions

There is an issue with formula processing. Here is a small example to illustrate.

y <- rcmp(250, lambda = 10, nu = 0.95)
# Doesn't work
out <- glm.cmp(y ~ 1)
out <- glm.cmp(y ~ 1, formula.nu = ~ 1)
# Workaround
out <- glm.cmp(y ~ 1, formula.nu = y ~ 1)

lotze / COMPoissonReg

z-function evaluating to infinity #11