am 337b0873: docs: update backup guide and bmgr tool elaborate the guide to testing a backup agent and add links between the docs

Merge commit '337b0873f43eac5f23483bec94bd8729f79d47ec' into gingerbread

* commit '337b0873f43eac5f23483bec94bd8729f79d47ec':
  docs: update backup guide and bmgr tool
tree: 234a0d3725db1acbc6af72d98e26da2ef513f68b
  1. awt/
  2. camera/
  3. cmds/
  4. include/
  5. libs/
  6. opengl/
  7. vpn/
  8. MODULE_LICENSE_APACHE2
  9. NOTICE