.categorySelector('expand', param) usage
   param = ':all'       Expand all the categories
 param = ':all=x'     Expand all the categories with level=x ; other are not
                       changed
 param = ':all<x'     Expand all the categories with level<=x ; other are not
                       changed
 param = ':all>x'     Expand all the categories with level>=x ; other are not
                       changed
 param = ':all+x'     Expand all the categories with level<=x ; other are
                       collapsed
 param = 'zzz'        Expand the categories with catId=zzz ; other are not
                       changed
 param = 'zzz+'       Expand the categories with catId=zzz ; parent categories
                       are expanded too, all other are collapsed
 param = 'zzz<'       Expand the categories with catId=zzz ; parent categories
                       are expanded too, all other are not changed
 param = 'zzz>'       Expand the categories with catId=zzz ; childs categories
                       are expanded too, all other are not changed