devel: add dkg's printmimestructure script to notmuch devel scripts

I find this script pretty useful when figuring out who to blame for
MIME rendering problems.

The notmuch repo will be the new primary home for this script, unless
and until a better home turns up.

diff --git a/devel/printmimestructure b/devel/printmimestructure
new file mode 100755 (executable)
index 0000000..34d1293
--- /dev/null
+++ b/devel/printmimestructure
@@ -0,0 +1,52 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+# Author: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
+# License: GPLv3+
+
+# This script reads a MIME message from stdin and produces a treelike
+# representation on it stdout.
+
+# Example:
+#
+# 0 dkg@alice:~$ printmimestructure < 'Maildir/cur/1269025522.M338697P12023.monkey,S=6459,W=6963:2,Sa'
+# └┬╴multipart/signed 6546 bytes
+#  ├─╴text/plain inline 895 bytes
+#  └─╴application/pgp-signature inline [signature.asc] 836 bytes
+# 0 dkg@alice:~$
+
+
+# If you want to number the parts, i suggest piping the output through
+# something like "cat -n"
+
+import email
+import sys
+
+def test(z, prefix=''):
+    fname = '' if z.get_filename() is None else ' [' + z.get_filename() + ']'
+    cset = '' if z.get_charset() is None else ' (' + z.get_charset() + ')'
+    disp = z.get_params(None, header='Content-Disposition')
+    if (disp is None):
+        disposition = ''
+    else:
+        disposition = ''
+        for d in disp:
+            if d[0] in [ 'attachment', 'inline' ]:
+                disposition = ' ' + d[0]
+    if (z.is_multipart()):
+        print prefix + '┬╴' + z.get_content_type() + cset + disposition + fname, z.as_string().__len__().__str__() + ' bytes'
+        if prefix.endswith('└'):
+            prefix = prefix.rpartition('└')[0] + ' '
+        if prefix.endswith('├'):
+            prefix = prefix.rpartition('├')[0] + '│'
+        parts = z.get_payload()
+        i = 0
+        while (i < parts.__len__()-1):
+            test(parts[i], prefix + '├')
+            i += 1
+        test(parts[i], prefix + '└')
+        # FIXME: show epilogue?
+    else:
+        print prefix + '─╴'+ z.get_content_type() + cset + disposition + fname, z.get_payload().__len__().__str__(), 'bytes'
+
+test(email.message_from_file(sys.stdin), '└')