core: Start of the big refactor for PieCrust 3.0. * Everything is a `ContentSource`, including assets directories. * Most content sources are subclasses of the base file-system source. * A source is processed by a "pipeline", and there are 2 built-in pipelines, one for assets and one for pages. The asset pipeline is vaguely functional, but the page pipeline is completely broken right now. * Rewrite the baking process as just running appropriate pipelines on each content item. This should allow for better parallelization.

--- a/piecrust/__init__.py	Sat Apr 29 21:42:22 2017 -0700
+++ b/piecrust/__init__.py	Wed May 17 00:11:48 2017 -0700
@@ -19,13 +19,13 @@
 
 PIECRUST_URL = 'https://bolt80.com/piecrust/'
 
-CACHE_VERSION = 29
+CACHE_VERSION = 30
 
 try:
     from piecrust.__version__ import APP_VERSION
 except ImportError:
     APP_VERSION = 'unknown'
 
-import os.path
+import os.path  # NOQA
 RESOURCES_DIR = os.path.join(os.path.dirname(__file__), 'resources')