Align RPC names in tables and use consistent lowercase "bitcoin-cli"

(Some extreme nitpicking for better readability, feel free to pick what you like)

Screenshot:
![capture du 2014-12-20 23 46 35](https://cloud.githubusercontent.com/assets/3578089/5517188/98542c62-88a2-11e4-9b2d-06431208888a.png)

@saivann thanks for the pull!  I like the break between the arrows and names, as well as the space between arrows.   However, I wanted to explain why I think we should drop the "(s)".  The way I was taught to name things, we use plural for a type that holds multiple things and singular for a type that holds only a single thing.  For example: for *object* in **objects** do f(*object*).  Based on this, I think each Parameter here holds a single parameter, even if it's an array or JSON object.  The fact that there can be multiple parameters is indicated by the plural name of the containing array---"params".  (And also explicitly by the text in the Presence field.)