Add Tools/scripts/patchcheck.py. Invoked from ``make check``, the script does
some verification:

- Runs reindent.py on all .py files.
- Checks if any changes in Doc exist.
- Whether Misc/ACKS was changed.
- Whether Misc/NEWS was changed.

The hope is that ``make check`` can become a command anybody can run to get
reminders about what all the requisite steps needed to create a proper
patch/checkin.
diff --git a/Makefile.pre.in b/Makefile.pre.in
index 61e7282..4edc784 100644
--- a/Makefile.pre.in
+++ b/Makefile.pre.in
@@ -1140,6 +1140,10 @@
 		-o -name MANIFEST \
 		-o -print
 
+# Perform some verification checks on any modified files.
+check:
+	./$(BUILDPYTHON) $(srcdir)/Tools/scripts/patchcheck.py
+
 # Dependencies
 
 Python/thread.o: @THREADHEADERS@