[Rd] Allowed quasibinomial links (PR#8851)

[henric.nilsson at statisticon.se]

Full_Name: Henric Nilsson
Version: 2.3.0 Patched (2006-05-09 r38014)
OS: Windows 2000 SP4
Submission from: (NULL) (83.253.9.137)


When supplying an unavailable link to `quasibinomial', the error message looks
strange. E.g.
> quasibinomial("x")
Error in quasibinomial("x") : 'x' link not available for quasibinomial family,
available links are "logit", ", ""probit" and "cloglog"
                          ^^^^^^^^
Clearly, something's missing. A quick peek in the code reveals that `log' is
allowed, but is missing from the above list.

Furthermore, shouldn't `quasibinomial' also allow the `cauchit' link?