Howto release doc additions

code/release-bugfix.rst
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  o Howto create a release branch patch

howto/release/overview.rst
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  o Early writeup of release actions.
  o Edits needed for both branch=release and branch=master

Change-Id: I34ecc54217b2f185f7737f3244fceb2a4ddf4c5d
5 files changed