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_find_releases.py b/git_find_releases.py
index ef65c0e..cab723d 100755
--- a/git_find_releases.py
+++ b/git_find_releases.py
@@ -11,6 +11,8 @@
 only work on merges that followed the "use cherry-pick -x" instructions.
 """
 
+from __future__ import print_function
+
 import optparse
 import re
 import sys
@@ -43,16 +45,16 @@
   for arg in args:
     commit_name = GetNameForCommit(arg)
     if not commit_name:
-      print '%s not found' % arg
+      print('%s not found' % arg)
       return 1
-    print 'commit %s was:' % arg
-    print '  initially in ' + commit_name
+    print('commit %s was:' % arg)
+    print('  initially in ' + commit_name)
     merges = GetMergesForCommit(arg)
     for merge in merges:
-      print '  merged to ' + GetNameForCommit(merge) + ' (as ' + merge + ')'
+      print('  merged to ' + GetNameForCommit(merge) + ' (as ' + merge + ')')
     if not merges:
-      print 'No merges found. If this seems wrong, be sure that you did:'
-      print '  git fetch origin && gclient sync --with_branch_heads'
+      print('No merges found. If this seems wrong, be sure that you did:')
+      print('  git fetch origin && gclient sync --with_branch_heads')
 
   return 0