More flexible, less error-prone configuration system.

WARNING: make a backup copy of your local config.py before pulling
this change, as Git will overwrite it without warning.

The configuration defaults to deployment settings, allowing overrides.
Overrides are read from config_local.py and from the file pointed to
by the PILLAR_CONFIG env var.

tests/config_testing.py

@@ -0,0 +1,8 @@
+"""Flask configuration file for unit testing."""
+
+BLENDER_ID_ENDPOINT = 'http://127.0.0.1:8001'  # nonexistant server, no trailing slash!
+
+DEBUG = True
+TESTING = True
+
+CDN_STORAGE_USER = 'u41508580125621'