diff -r 000000000000 -r 6474c204b198 addon-sdk/source/python-lib/cuddlefish/util.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/addon-sdk/source/python-lib/cuddlefish/util.py	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,23 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+IGNORED_FILE_PREFIXES = ["."]
+IGNORED_FILE_SUFFIXES = ["~", ".swp"]
+IGNORED_DIRS = [".git", ".svn", ".hg"]
+
+def filter_filenames(filenames, ignored_files=[".hgignore"]):
+    for filename in filenames:
+        if filename in ignored_files:
+            continue
+        if any([filename.startswith(suffix)
+                for suffix in IGNORED_FILE_PREFIXES]):
+            continue
+        if any([filename.endswith(suffix)
+                for suffix in IGNORED_FILE_SUFFIXES]):
+            continue
+        yield filename
+
+def filter_dirnames(dirnames):
+    return [dirname for dirname in dirnames if dirname not in IGNORED_DIRS]