Update in LMMstar user interface

[bozenne]

The R syntax of the tutorial is anticipated to undergo one visible change when the next version of the LMMstar package is released to improve the user interface:
proportion(e.mlmm, method = "single-step", n.sample = 0)
will be called replaced by
confint(e.mlmm, method = "proportion", columns = c("estimate","se","df","lower","upper","p.value"))
or
model.tables(e.mlmm, method = c("average","pool.fixse","pool.gls","pool.gls1","proportion))
similarly to the other estimators.

[bozenne]

The output of summary(e.mlmm) should also be fix (currently it says mixed model and it should say linear model)