Add project annotation handling to repo

Allow the optional addition of "annotation" nodes nested under
projects.  Each annotation node must have "name" and "value"
attributes.  These name/value pairs will be exported into the
environment during any forall command, prefixed with "REPO__"

In addition, an optional "keep" attribute with case insensitive "true"
or "false" values can be included to determine whether the annotation
will be exported with 'repo manifest'

Change-Id: Icd7540afaae02c958f769ce3d25661aa721a9de8
Signed-off-by: James W. Mills <jameswmills@gmail.com>

project.py

@@ -213,6 +213,11 @@ class DiffColoring(Coloring):
     Coloring.__init__(self, config, 'diff')
     self.project   = self.printer('header',    attr = 'bold')
 
+class _Annotation:
+  def __init__(self, name, value, keep):
+    self.name = name
+    self.value = value
+    self.keep = keep
 
 class _CopyFile:
   def __init__(self, src, dest, abssrc, absdest):
@@ -529,6 +534,7 @@ class Project(object):
 
     self.snapshots = {}
     self.copyfiles = []
+    self.annotations = []
     self.config = GitConfig.ForRepository(
                     gitdir = self.gitdir,
                     defaults =  self.manifest.globalConfig)
@@ -1175,6 +1181,9 @@ class Project(object):
     abssrc = os.path.join(self.worktree, src)
     self.copyfiles.append(_CopyFile(src, dest, abssrc, absdest))
 
+  def AddAnnotation(self, name, value, keep):
+    self.annotations.append(_Annotation(name, value, keep))
+
   def DownloadPatchSet(self, change_id, patch_id):
     """Download a single patch set of a single change to FETCH_HEAD.
     """