Convert print statements to Python 3 style

Ran "2to3 -w -n -f print ./" and manually added imports.
Ran "^\s*print " and "\s+print " to find batch/shell scripts, comments and the like with embedded code, and updated them manually.
Also manually added imports to files, which used print as a function, but were missing the import.

The scripts still work with Python 2.
There are no intended behaviour changes.

Bug: 942522
Change-Id: Id777e4d4df4adcdfdab1b18bde89f235ef491b9f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/1595684
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Commit-Queue: Dirk Pranke <dpranke@chromium.org>
Auto-Submit: Raul Tambre <raul@tambre.ee>
diff --git a/git_cl.py b/git_cl.py
index a92cafe..8f82be4 100755
--- a/git_cl.py
+++ b/git_cl.py
@@ -1998,14 +1998,14 @@
       if gerrit_auth == git_auth:
         return
       all_gsrc = cookie_auth.get_auth_header('d0esN0tEx1st.googlesource.com')
-      print((
+      print(
           'WARNING: You have different credentials for Gerrit and git hosts:\n'
           '           %s\n'
           '           %s\n'
           '        Consider running the following command:\n'
           '          git cl creds-check\n'
           '        %s\n'
-          '        %s') %
+          '        %s' %
           (git_host, self._gerrit_host,
            ('Hint: delete creds for .googlesource.com' if all_gsrc else ''),
            cookie_auth.get_new_password_message(git_host)))