allow lw,ls for filled contour styling (#98)

* allow lw,ls for filled contour styling

* tweak

getdist/plots.py

@@ -1078,12 +1078,8 @@ def add_2d_contours(self, root, param1=None, param2=None, plotno=0, of=None, col
         else:
             proxy_ix = -1
 
-        def clean_args(_args):  # prevent unused argument warnings
-            _args = dict(_args)
-            _args.pop('color', None)
-            _args.pop('ls', None)
-            _args.pop('lw', None)
-            return _args
+        def clean_args(_args):
+            return {k: v for k, v in _args.items() if k not in ('color', 'ls', 'lw')}
 
         if kwargs.get('filled'):
             if cols is None:
@@ -1101,13 +1097,15 @@ def clean_args(_args):  # prevent unused argument warnings
                 self.contours_added[proxy_ix] = (
                     matplotlib.patches.Rectangle((0, 0), 1, 1, fc=matplotlib.colors.to_rgb(cs.tcolors[-1][0])))
             ax.contour(density.x, density.y, density.P, levels[:1], colors=cs.tcolors[-1],
-                       linewidths=self._scaled_linewidth(self.settings.linewidth_contour),
+                       linewidths=self._scaled_linewidth(self.settings.linewidth_contour
+                                                         if kwargs.get('lw') is None else kwargs['lw']),
+                       linestyles=kwargs.get('ls'),
                        alpha=alpha * self.settings.alpha_factor_contour_lines, **clean_args(kwargs))
         else:
             args = self._get_line_styles(plotno, **kwargs)
             linestyles = [args['ls']]
             cols = [args['color']]
-            lws = args['lw']  # not linewidth_contour is only used for filled contours
+            lws = args['lw']  # note linewidth_contour is only used for filled contours
             kwargs = self._get_plot_args(plotno, **kwargs)
             kwargs['alpha'] = alpha
             cs = ax.contour(density.x, density.y, density.P, sorted(contour_levels), colors=cols, linestyles=linestyles,