Make message the full message and add a summary property

Adds a summary property to the Commit object which returns just the first line of the commit message and makes the message property contain the entire commit message (previously the message property only contained the first line of the commit message).  This breaks backwards compatibility a little in that the message property now contains a different value but previously there was no way to access the entire commit message from the Commit object and this is in keeping with git vocabulary, where message generally refers to the entire commit message.
(cherry picked from commit 9d2962d8306c894d4cca55bab551677b92d96352)

Author: Paul Sowden

lib/git/commit.py

@@ -41,7 +41,7 @@ def __init__(self, repo, id, tree=None, author=None, authored_date=None,
             is the committed DateTime
 
         ``message``
-            is the first line of the commit message
+            is the commit message
 
         ``parents``
             is the list of the parents of the commit
@@ -81,6 +81,10 @@ def __bake__(self):
     def id_abbrev(self):
         return self.id[0:7]
 
+    @property
+    def summary(self):
+        return self.message.split('\n', 1)[0]
+
     @classmethod
     def count(cls, repo, ref, path=''):
         """
@@ -159,7 +163,7 @@ def list_from_string(cls, repo, text):
             while lines and lines[0].startswith('    '):
                 messages.append(lines.pop(0).strip())
 
-            message = messages and messages[0] or ''
+            message = '\n'.join(messages)
 
             commits.append(Commit(repo, id=id, parents=parents, tree=tree, author=author, authored_date=authored_date, 
                                   committer=committer, committed_date=committed_date, message=message))

test/git/test_repo.py

@@ -67,7 +67,7 @@ def test_commits(self, git):
 
         c = commits[2]
         assert_equal(["6e64c55896aabb9a7d8e9f8f296f426d21a78c2c", "7f874954efb9ba35210445be456c74e037ba6af2"], map(lambda p: p.id, c.parents))
-        assert_equal("Merge branch 'site'", c.message)
+        assert_equal("Merge branch 'site'", c.summary)
 
         assert_true(git.called)
         assert_equal(git.call_args, (('rev_list', 'master', '--', ''), {'skip': 0, 'pretty': 'raw', 'max_count': 10}))