Document the Riak CS connection pool settings

Add documentation about the Riak CS connection pool settings. Describe
the difference between the two connection pools currently used by Riak
CS, describe the meaning of the configuration pair, and provide some
guidance on sizing and tuning.
Minor edits to correct typos and address review feedback
Adjust wording of pb_backlog tuning section and fix typo from review feedback
Update to Riak CS configuration doc based on review comments
Update README to make link Markdown
Merge pull request #1234 from danielcompton/patch-1

Update README to make link Markdown
More accurate language for node_puts

If a local vnode is not part of the preflist then the put_fsm is not run on the receiving node, but moved to a node which contains a vnode in the preflist.
Merge pull request #1240 from basho/dbrown-inspecting_a_node

More accurate language for node_puts
polish language a bit
polish up configuring riak doc
Merge pull request #1218 from basho/feature/klm/cs-connection-pools

Document the Riak CS connection pool settings
merge to master