Create locals file for local configuration and testing variables. Move variable-based files to a var folder.

.gitignore

@@ -245,3 +245,6 @@ app.*.map.json
 
 # Do not post secrets!
 secrets.dart
+
+# Keep locals local.
+locals.dart

lib/var/locals.dart.EXAMPLE

@@ -0,0 +1,3 @@
+// This file needs renamed `local.dart` if implemented.
+
+const bool debug = false;