minor stdlib fixes

stdlib/Std/src/Geo.luna

@@ -1,13 +1,13 @@
 import Std.Base
 
 class GeoJSONFeature:
-    properties :: Map Text JSON
+    properties :: JSON
     geometry   :: JSON
 
-    def toJSON: Tip . insert "type" (JSONString "Feature") . insert "properties" self.properties.toJSON . insert "geometry" self.geometry . toJSON
+    def toJSON: JSON . empty . insert "type" "Feature" . insert "properties" self.properties . insert "geometry" self.geometry
 
 class GeoJSONFeatureCollection:
 
     features :: List GeoJSONFeature
 
-    def toJSON: Tip . insert "type" (JSONString "FeatureCollection") . insert "features" self.features.toJSON . toJSON
+    def toJSON: JSON . empty . insert "type" "FeatureCollection" . insert "features" self.features

stdlib/Std/src/HTTP.luna

@@ -115,7 +115,7 @@ class HttpRequest:
     ## a valid Http header name, like `Accept-Charset` (but the case
     ## does not matter).
     def addHeader key val: case self of
-        HttpRequest uri method _ auth oauth1 params body:
+        HttpRequest uri method headers auth oauth1 params body:
             HttpRequest uri method (headers.insert key val) auth oauth1 params body
 
     ## Use the provided username and password as `HttpBasicAuth`.