Fix release notes formatting

Release 0.4.3 has overwritten 0.4.2 release notes and is missing some
formatting.
diff --git a/CHANGELOG.md b/CHANGELOG.md
index c855d3d..d6a6385 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,6 @@
 ## Release 0.4.3 (2016-12-22)
 
+```
 Baseline: c645a45
 
 Cherry picks:
@@ -23,6 +24,7 @@
    + 4975760: Fix PathFragment to not use Java8-only static hashCode
               methods.
    + 05fd076: Disable sandboxing for XibCompile actions.
+```
 
 Incompatible changes:
 
@@ -45,6 +47,32 @@
   - Skylark dicts internally don't rely on keys order anymore and
     accept any hashable values (i.e. structs with immutable values)
     as keys. Iteration order of dictionaries is no longer specified.
+
+## Release 0.4.2 (2016-12-02)
+
+```
+Baseline: 6331a94
+
+Cherry picks:
+   + 7b835d9: Do not patch WORKSPACE in the release process
+```
+
+Incompatible changes:
+
+  - Callback functions in Skylark no longer support the cfg
+    parameter. This is a cleanup and only affects the signatures of
+    callbacks, since the parameter hasn't been set since September
+    2016.
+
+Important changes:
+
+  - Alias proto_library's produce a descriptor set that contains all
+    srcs of its dependencies.
+  - proto_library supports strict proto deps.
+  - Top level @androidsdk support library targets have been replaced
+    by @androidsdk//<group id>:<artifact id>-<version> for Android
+    SDK Support and Google Play Services libraries.
+
 ## Release 0.4.1 (2016-11-21)
 
 ```