better pointers to the  'plots.thpr.Rd'  help page
optwrap() , adj=TRUE, "Nelder_Mead":  fix 'xst' logic
  {{ and where did BB get magic factor 0.2 from ?}}
- new logProf() which allows to have  log(sigma) and sigma01 (*non*-logged)
  via ranef=FALSE
- eliminate not-exported  varpr() which will be an accidental duplication
  of varianceProf()
- fix varianceProf() to keep the fixed effects {as log(<profile) does}, but
  does adapt the column names of transformed; also allows ranef;
- stripExpr() adapted to work with varianceProf() result
also 40164ff : + logProf
keep 'method' for "optimx"
first step to not only *fit* with many methods, but then also be able to
profile() with that optimizer setup