[Rd] Documentation examples for lm and glm

[Thomas Yee]

Hello,

something that has been on my mind for a decade or two has
been the examples for lm() and glm(). They encourage poor style
because of mismanagement of data frames. Also, having the
variables in a data frame means that predict()
is more likely to work properly.

For lm(), the variables should be put into a data frame.
As 2 vectors are assigned first in the general workspace they
should be deleted afterwards.

For the glm(), the data frame d.AD is constructed but not used. Also,
its 3 components were assigned first in the general workspace, so they
float around dangerously afterwards like in the lm() example.

Rather than attached improved .Rd files here, they are put at
www.stat.auckland.ac.nz/~yee/Rdfiles
You are welcome to use them!

Best,

Thomas