masking ranef (from "nlme" or "lme4")

[mmaechler]

The metafor package provides an S3 method for ranef(). Because it "forgets" to import the S3 generic (from nlme or lme4), a new ranef() S3 generic is automatically created.

This leads to a warning in the following, but more importantly, ranef() will stop working for nlme or lme4 objects where it should work:

> require(nlme)
> require(metafor)
Loading required package: metafor
Loading 'metafor' package (version 1.9-9). For an overview 
and introduction to the package please type: help(metafor).

Attaching package: ‘metafor’

The following object is masked from ‘package:lme4’:

    ranef

AFTER fixing the problem (see pull request) the warning (" ... masked ... " ) disappears and more importantly, after loading the two packages, methods(ranef) does show both nlme and metafor methods.