Introducing Pillar Framework

Refactor of pillar-server and pillar-web into a single python package. This
simplifies the overall architecture of pillar applications.

Special thanks @sybren and @venomgfx

pillar/extension.py

@@ -0,0 +1,64 @@
+"""Pillar extensions support.
+
+Each Pillar extension should create a subclass of PillarExtension, which
+can then be registered to the application at app creation time:
+
+    from pillar_server import PillarServer
+    from attract_server import AttractExtension
+
+    app = PillarServer('.')
+    app.load_extension(AttractExtension(), url_prefix='/attract')
+    app.process_extensions()  # Always process extensions after the last one is loaded.
+
+    if __name__ == '__main__':
+        app.run('::0', 5000)
+
+"""
+
+import abc
+
+
+class PillarExtension(object):
+    __metaclass__ = abc.ABCMeta
+
+    @abc.abstractproperty
+    def name(self):
+        """The name of this extension.
+
+        The name determines the path at which Eve exposes the extension's
+        resources (/{extension name}/{resource name}), as well as the
+        MongoDB collection in which those resources are stored
+        ({extensions name}.{resource name}).
+
+        :rtype: unicode
+        """
+
+    @abc.abstractmethod
+    def flask_config(self):
+        """Returns extension-specific defaults for the Flask configuration.
+
+        Use this to set sensible default values for configuration settings
+        introduced by the extension.
+
+        :rtype: dict
+        """
+
+    @abc.abstractmethod
+    def blueprints(self):
+        """Returns the list of top-level blueprints for the extension.
+
+        These blueprints will be mounted at the url prefix given to
+        app.load_extension().
+
+        :rtype: list of flask.Blueprint objects.
+        """
+
+    @abc.abstractmethod
+    def eve_settings(self):
+        """Returns extensions to the Eve settings.
+
+        Currently only the DOMAIN key is used to insert new resources into
+        Eve's configuration.
+
+        :rtype: dict
+        """