Add information about lava-network cache file.

Change-Id: I01fcafaf238f472bc9ce892eeb894335c66989ba
Fix PEP8 in unit test.

Change-Id: I05e9123045405fd23d0a8aba9a5b786d387653f5
doc: Fix bugs, code review and git references.

  * Change the git reference URL, to point to the exact project
    list.
  * Updated the bug link to bugs.linaro.org.
  * Add reference to register.linaro.org.
  * Fix patch process: use review.linaro.org.

Change-Id: Ie390192b0789a87e05dc76e9d7abb49895c81f79
Fix bug #359 - Possible regression in multinode device_tags selection

See https://bugs.linaro.org/show_bug.cgi?id=359

Change-Id: Idbd65dea556928294a6c50aca0727a5a90251cc2