Slightly improve source path tree in the browser debugger

webpack.config.js

@@ -11,6 +11,18 @@ module.exports = {
             { test: /\.js$/, loader: "babel", include: path.resolve('./src') },
         ]
     },
+    output: {
+        devtoolModuleFilenameTemplate: function(info) {
+            // Reading input source maps gives only relative paths here for
+            // everything. Until I figure out how to fix this, this is a
+            // workaround.
+            // We use the relative resource path with any '../'s on the front
+            // removed which gives a tree with matrix-react-sdk and vector
+            // trees smashed together, but this fixes everything being under
+            // various levels of '.' and '..'
+            return info.resourcePath.replace(/^[\/\.]*/, '');
+        }
+    },
     resolve: {
         alias: {
             // alias any requires to the react module to the one in our path, otherwise