Inject the project name into each projects groups.

For CrOS, we have scenarios were people checkout a smaller version
of our manifest via groups, and enable individual repositories as
needed for their work.  Previously this was via local_manifest
manipulation, which breaks via manifest-groups would require a
remove-project tag.

Via injecting the projects name into the projects groups, this
allows us to instead manipulate the configured groups allowing
the user to turn on/off projects as necessary.

Change-Id: I07b7918e16cc9dc28eb47e19a46a04dc4fd0be74

docs/manifest-format.txt

@@ -171,7 +171,11 @@ the default element is used.
 
 Attribute `groups`: List of groups to which this project belongs,
 whitespace or comma separated.  All projects belong to the group
-"default".
+"default", and each project automatically belongs to a group of
+it's name:`name` and path:`path`.  E.g. for
+<project name="monkeys" path="barrel-of"/>, that project
+definition is implicitly in the following manifest groups:
+default, name:monkeys, and path:barrel-of.
 
 Element annotation
 ------------------

manifest_xml.py

@@ -566,8 +566,9 @@ class XmlManifest(object):
     if node.hasAttribute('groups'):
       groups = node.getAttribute('groups')
     groups = [x for x in re.split('[,\s]+', groups) if x]
-    if 'default' not in groups:
+
-      groups.append('default')
+    default_groups = ['default', 'name:%s' % name, 'path:%s' % path]
+    groups.extend(set(default_groups).difference(groups))
 
     if self.IsMirror:
       relpath = None