optim_sa_Wofost: WOFOST parameter optimisation
In achtmalklug/rwofost: R interface for WOFOST 7.1

Optimisation of WOFOST crop and management parameters (for calibration). This wraps runWofost for using with optimization::optim_sa. Since runWofost needs some extra info that optim_sa does not include in the function call, some Global variables are set for this.

optim_sa_Wofost(parfiles, wofostbin = .GlobalEnv$wofostbin,
  wofostdir = .GlobalEnv$wofostdir, qualityfun = .GlobalEnv$qualityfun,
  start, lower, upper, control = list(nlimit = 1, maxgood = 1),
  maximization = T)

`parfiles`	character vector: which parfiles to manipulate
`wofostbin`	wofost executable (under unixoid systems use "wine wofost.exe")
`wofostdir`	path in which the wofost executable resides (without the actual execuatable name)
`qualityfun`	the function to be evaluated after wofost run
`start`	named numeric vector with the start values
`lower`	named numeric vector with the lower bounds (names must be the names of the parameters to manipulate)
`upper`	named numeric vector with the upper bounds
`control`	the control list passed to optim_sa
`maximization`	maximization instead of minimization of the
`parameters`	named vector: the parameters with their values to set
`parfiles`	chracter vectore with the parameter files to be manipulated