minor #1455 complete the changelog file for 1.7 (xabbuh)

This PR was merged into the 1.7 branch.

Discussion
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complete the changelog file for 1.7

I forgot to mark #1449 as "WIP". So this PR adds the missing pieces.

Commits
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05bdba3 complete the changelog file for 1.7

Author: xabbuh

CHANGELOG.md

@@ -1,12 +1,25 @@
 CHANGELOG
 =========
 
+* fixed the `AllowedMethodsRouteLoader` to work with Symfony 3.0
+
 1.7.8
 -----
 
+* removed uses of the reflection API in favor of faster solutions when possible
+
+* fixed the configuration to use serialization groups and versions at the same time
+
 1.7.7
 -----
 
+* when using Symfony 3.x, the bundle doesn't call methods anymore that have been deprecated in
+  Symfony 2.x and were removed in Symfony 3.0
+
+* the `ViewResponseListener` does not overwrite explicitly configured templates anymore
+
+* fixed the `ParamFetcher` class to properly handle sub requests
+
 1.7.6
 -----