mst.setalbedovalue() can be extended with a "v","p",w" flag to be valid for any surface type

[stefanfluck]

right now it is assumed that the vegetation albedo is changed. adding a flag, it could modify any pars array. either with a flag this can be done, or multiple implementations with pavpars or watpars instead of vegpars int he function call. the latter may be cleaner.

[stefanfluck]

is this somehow related to #25 ? not entirely, since this is about setting albedo values. but, the flag idea could be useful? however, this represents an "edge" case and not part of the key palmpy functionality.