Update .mailmap

Update Ian Jackson's email address as requested in
<https://lists.debian.org/debian-dpkg/2015/09/msg00015.html>.

Reverse Michael Vogt @ubuntu.com local part mapping, following the form
in the most recent commits.

Other updates taken from dpkg's mailmap file.

.mailmap

@@ -1,18 +1,28 @@
-# Unify user identities
-Christian Perrier <[email protected]>
-<[email protected]> <ian@anarres>
-<[email protected]> <ian@liberator>
+# Aliases
+<[email protected]> <[email protected]>
+
+# Use real mail addresses
+<[email protected]> <ian@anarres>
+<[email protected]> <ian@liberator>
 <[email protected]> <jackyf@1501-debian>
 Michael Vogt <[email protected]> <egon@debian-vm>
 <[email protected]> <egon@bottom>
 <[email protected]> <egon@debian-devbox>
 <[email protected]> <egon@pop>
 <[email protected]> <egon@tas>
-<[email protected]> <[email protected]>
-# Name changes
-Peter Krefting <[email protected]>
-# Email as user name
+
+# Very broken names
 Christian Perrier <[email protected]> [email protected] <>
 Julian Andres Klode <[email protected]> [email protected] <>
 Loïc Minier <[email protected]> [email protected] <>
 Martin Pitt <[email protected]> [email protected] <>
+
+# Spell names properly
+Christian Perrier <[email protected]>
+Joe Hansen <[email protected]>
+Johannes Schauer Marin Rodrigues <[email protected]>
+Johannes Schauer Marin Rodrigues <[email protected]>
+Johannes Schauer Marin Rodrigues <[email protected]>
+Michael Vogt <[email protected]>
+Peter Krefting <[email protected]>
+Trần Ngọc Quân <[email protected]>