DevDocs corrections part 1

Started reviewing the developer docs, finding lots of things to correct. I'll do more later, but please review this batch first so I know what, if anything, needs to be fixed moving forward - I'm not entirely sure on the markdownish format used.
Then how about, "difficulty value expected by the network consensus".  As stated in my original comment, my (minor) issue is with treating the block chain as an animate object that has expectations.  To me, the block chain is just a collection of data, like the log files on my computer.