Add a project progress meter to 'repo sync'

This way users can see how much is left during fetch.  Its
especially useful when most syncs are no-ops but there are
hundreds of repositories to poll.

Signed-off-by: Shawn O. Pearce <sop@google.com>

progress.py

@@ -0,0 +1,45 @@
+#
+# Copyright (C) 2009 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import sys
+
+class Progress(object):
+  def __init__(self, title, total):
+    self._title = title
+    self._total = total
+    self._done = 0
+    self._lastp = -1
+
+  def update(self, inc=1):
+    self._done += inc
+    p = (100 * self._done) / self._total
+
+    if self._lastp != p:
+      self._lastp = p
+      sys.stderr.write('\r%s: %3d%% (%d/%d)  ' % (
+        self._title,
+        p,
+        self._done,
+        self._total))
+      sys.stderr.flush()
+
+  def end(self):
+    p = (100 * self._done) / self._total
+    sys.stderr.write('\r%s: %3d%% (%d/%d), done.  \n' % (
+      self._title,
+      p,
+      self._done,
+      self._total))
+    sys.stderr.flush()