tools/sort_sources.py: sort C++ source file names in build files.

tools/sort-headers.py

Index: tools/sort-headers.py
diff --git a/tools/sort-headers.py b/tools/sort-headers.py
index 3f3435d56b514fca1b56863a479af23dd5355fe5..5e8fc2641f261e502fcb30c64ed80ecc9a4944c9 100755
--- a/tools/sort-headers.py
+++ b/tools/sort-headers.py
@@ -13,28 +13,7 @@ import optparse
 import os
 import sys
 
-
-def YesNo(prompt):
-  """Prompts with a yes/no question, returns True if yes."""
-  print prompt,
-  sys.stdout.flush()
-  # http://code.activestate.com/recipes/134892/
-  if sys.platform == 'win32':
-    import msvcrt
-    ch = msvcrt.getch()
-  else:
-    import termios
-    import tty
-    fd = sys.stdin.fileno()
-    old_settings = termios.tcgetattr(fd)
-    ch = 'n'
-    try:
-      tty.setraw(sys.stdin.fileno())
-      ch = sys.stdin.read(1)
-    finally:
-      termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
-  print ch
-  return ch in ('Y', 'y')
+from yes_no import YesNo
 
 
 def IncludeCompareKey(line):