Create a mailmap

  - This patch adds a mailmap which is aim to map
  addresses in bzr to people's real,preferred e-mail addresses.
  - Add an alias for Xingchao Yu.

Change-Id: I427ef5bdfbf636476f3b788a9642abcb285fc775
add rbd backend support to glance

Change-Id: I03b59e627b66e744a6efe45db24b8929e75f5e2e
Merge "Create a mailmap"
Merge "add rbd backend support to glance"