fix 2 syntax errors
2 more buglets squashed.
mice.r: deleted old, incorrect setting of extra names
internal.r correct handling of type
type, from the predictorMatrix, is used actively by various 2l imputers.
padModel used to rearrange it, but with its demise we have to.
Conceivably this processing should be done in mice()'s checkForm function.
Note also that I preserve some other info that may be useful, and probably
should be passed back up.  In particular, it would be good to know what
levels correspond to what coefficients.
This doesn't quite fit the extra model since it is computed above the level
of the specific imputer (and therefore doesn't know what class of extra to create),
and because it's computed only once per variable.