Changes for 4.2.1

Also document the kernels better, and fine-tune the details about N7 support.

Bug: 4445289
Change-Id: I72658c600174cfbe02be54e5bdbbede01cd72d64
diff --git a/src/source/build-numbers.md b/src/source/build-numbers.md
index d41700d..9a248dd 100644
--- a/src/source/build-numbers.md
+++ b/src/source/build-numbers.md
@@ -43,7 +43,7 @@
 Ice Cream Sandwich | 4.0.1 - 4.0.2 | API level 14, NDK 7
 Ice Cream Sandwich | 4.0.3 - 4.0.4 | API level 15, NDK 8
 Jelly Bean       | 4.1.x         | API level 16
-Jelly Bean       | 4.2           | API level 17
+Jelly Bean       | 4.2.x         | API level 17
 
 Starting with Cupcake, individual builds are identified with a short
 build code, e.g. FRF85B.
@@ -126,7 +126,8 @@
 JRO03R | android-4.1.1_r6   | Nexus S 4G
 JRO03S | android-4.1.1_r6.1 | Nexus 7
 JZO54K | android-4.1.2_r1   | Nexus S, Galaxy Nexus, Nexus 7
-JOP40C | android-4.2_r1     | latest Jelly Bean version, Galaxy Nexus, Nexus 7, Nexys 4, Nexus 10
+JOP40C | android-4.2_r1     | Galaxy Nexus, Nexus 7, Nexus 4, Nexus 10
+JOP40D | android-4.2.1_r1   | latest Jelly Bean version, Galaxy Nexus, Nexus 7, Nexus 4, Nexus 10
 
 The branches froyo, gingerbread, ics-mr0, ics-mr1, jb-dev,
 jb-mr1-dev,