BUGS/ISSUES:

* proper initialization of intercept-less parameter()
    entries

* plot methods/fortify, a la ggplot2?

* add deviance() method [need S3-to-S4 conversion]

* make sure subset arg is really working!

* spurious error on mismatched parameter names

* spurious warnings in 1-parameter conf int:

   library(bbmle)
   m1 <- mle2(10~dbinom(prob=p,size=15),start=list(p=0.67))
   c1 <- confint(m1)

* issues when hitting new minimum in confint rather than
profile; should return unevaluated call too in this case

* use numDeriv library hessian() function instead of nlme::fdHess?
(or use nlme::fdHess to avoid loading whole package?)

* turn off Hessian calculation for profile fits??

* should print warning immediately if convergence fails

* some weird stuff with returned fit from found-better-fit profile --
treating profiled value as fixed ...

BUG:   order of parameters matters for L-BFGS-B
  (fixed)

  adjusting parameter vectors for lower, upper, parscale, ...
    when some params are fixed ...

  sort out names BS -- when can we safely remove names?


TO DO:

model-averaging?

more documentation -- especially S4 methods!
   especially:
     profile
     plot profile
     confint

catch/interpret more error messages?
  (try to filter last.warning?)

add DIC to IC tabs?
lmer?

WISHLIST:
start as FUNCTION (i.e., self-start)
analytic derivatives
relist
subset
plot.predict
drop1, add1, etc.
link functions ("identity","log", "logit", etc.)
delta method standard error calcs
tranformations on LHS of formula (i.e. use
  link rather than inverse-link function?  only
  possible if link is known and invertible:

   inverse 
   log
   logit  (qlogis)
   probit (qnorm)

  etc.

clean up/argue about data handling: closures etc. etc. etc...

document argument handling:

  start must be a named vector or a named list
       [OR?? inherit from parnames(minuslogl)?]
  if start is not a list (i.e. a numeric vector)
  set vecpar TRUE
  convert start to a list

  if missing and default.start is TRUE use formals(minuslogl)