Update the documentation with the relevant changes pertaining to
the new behaviour of ResourceBase.refresh() [0] method.
Also, removed CPU and memory information from 'Missing Features'
portion as those are available now.
[0] Commit patch 2b39751e19
Change-Id: Ifb81e0c58d70097eda1f65c9dbec13803056111c
b4cb4aaaa8