Coding style cleanup

Fix the following issues reported by pylint:

C0321: More than one statement on a single line
W0622: Redefining built-in 'name'
W0612: Unused variable 'name'
W0613: Unused argument 'name'
W0102: Dangerous default value 'value' as argument
W0105: String statement has no effect

Also fixed a few cases of inconsistent indentation.

Change-Id: Ie0db839e7c57d576cff12d8c055fe87030d00744
diff --git a/subcmds/manifest.py b/subcmds/manifest.py
index 4388765..5592a37 100644
--- a/subcmds/manifest.py
+++ b/subcmds/manifest.py
@@ -35,14 +35,14 @@
 
   @property
   def helpDescription(self):
-    help = self._helpDescription + '\n'
+    helptext = self._helpDescription + '\n'
     r = os.path.dirname(__file__)
     r = os.path.dirname(r)
     fd = open(os.path.join(r, 'docs', 'manifest-format.txt'))
     for line in fd:
-      help += line
+      helptext += line
     fd.close()
-    return help
+    return helptext
 
   def _Options(self, p):
     p.add_option('-r', '--revision-as-HEAD',