PCB net and parameter overhaul

- merge static and parametric nets
- allow dynamic nets on the fly with `p.local_net()`
- support local-to-global position calculations with `p.xy()`
  - this also enables intra-footprint traces and zones
- add anchor type parameters to footprints

src/ergogen.js

@@ -27,6 +27,7 @@ module.exports = {
         const points = points_lib.parse(config.points, units)
         if (debug) {
             results.points = points
+            results.demo = points_lib.visualize(points)
         }
 
         logger('Generating outlines...')
@@ -55,5 +56,6 @@ module.exports = {
 
         return results
     },
-    visualize: points_lib.visualize
+    visualize: points_lib.visualize,
+    inject_footprint: pcbs_lib.inject_footprint
 }