Working main Rlme function

I created a function called "rlme" that, given a formula, data, and a
method to use, modifies the data correctly and feeds it into the right
method. All the column names are taken from the formula, it isn't
dependent on columns being named anythings specific. The big drawback
right now is that it expects exactly two covariates, one school effect,
and one section effect. This is something I'll have to work on. Also,
the output is somewhat limited right now, it needs to be expanded and
beautified.