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.
Mmh, to be honest, I think most links on the Community page aren't really suitable for developers. IMO renaming "Bitcoin Forum" to "BitcoinTalk" would be fine, BitcoinTalk isn't used much for development, but that still looks like an useful place to ask technical questions.