byteify-strings: add --version argument

This is indispensable for automated tools to detect changes in behavior.

contrib/byteify-strings.py

@@ -278,6 +278,8 b' def editinplace(fname):'
 
 def main():
     ap = argparse.ArgumentParser()
+    ap.add_argument('--version', action='version',
+                    version='Byteify strings 1.0')
     ap.add_argument('-i', '--inplace', action='store_true', default=False,
                     help='edit files in place')
     ap.add_argument('--dictiter', action='store_true', default=False,

tests/test-byteify-strings.t

@@ -4,6 +4,11 b''
   >   $PYTHON "$TESTDIR/../contrib/byteify-strings.py" "$@"
   > }
 
+Test version
+
+  $ byteify_strings --version
+  Byteify strings * (glob)
+
 Test in-place
 
   $ cat > testfile.py <<EOF